Hey Nick, I have a th350 with four (4) forward frictions (light duty) rather than the "standard" five (5) frictions can the piston be machined to accept the 5th plate or can I swap a piston from a five (5) friction forward clutch in to accommodate the "standard" 5th friction? This is not the direct drive drum/piston but actually the forward drum/piston. Thanks
Hi Micheal, thanks for watching...Yes, you can machine the piston - just make sure the bottom steel doesn't fit under the lugs otherwise you'll have a no-apply condition in the drum thus no forward movement.
Another very informative and applicable video. The direct drum bleed hole recommendation is interesting. For a street machine that sees occasional strip time and regularly shifts at 6,000 rpm, how important is it to drill this hole? Thanks again for the great content!
Hi John, thank you for the kind words! If you're using high rate return springs and done all the other usual mods for this sort of application AND the trans is modulated AND retains its automatic forward shift pattern, a .035-.045 bleed hole should work. If you're not 100% sure, you can always install the high rate return springs and take it on a couple test passes to see if you detect either drag or centrifugal apply then make a decision from there...I'd drill it it it were mine...
Thank for the reply. I'm using a TCI full manual valve body (no trans brake). This also eliminates the auto function and modulating. I hadn't considered the high rate return springs. I do have a cut direct apply piston with a 5 clutch stack. Measuring .045 to .050" clearance with stock steels and no wave plate. I'm not sure I would be able to recognize direct clutch drag on a test. What would the signs be? What would be the consequence on a weekend only hot rod to forego the bleed hole? Thanks again fit the expert advice.
You're welcome...If going full manual trans brake, I'd add the bleed hole, especially if you're not using high rate return springs but those are strongly advised. If you're dragging you'll feel it when in 1st and 2nd and if the clutch comes on via centrifugal apply when in first, you may or may not bind or if in 2nd it will feel like a stack shift (i.e. earlier than normal/expected when considering how you have set up your governor). I'd drill but there's no real harm in trying to see how it does without the hole and go from there assuming you install the high rate return springs. Worst case, you replace any glazed frictions and re-prep steels. Either way, please let me know what you decide to do and what happens!
Ill watch it later today when i have time but yes the drum doesnt spin, prob a slip of the tongue when meaning to say something else. I may have been talking about the intermediate sprag rotation and its role in the transmission achiving second gear.
Hi Nick, I am having TH350 end play difficulty. Checking it as you do here I can not feel any...with a dial indicator and a small screw driver to pry up on the input shaft I am getting .002. I have checked and rechecked bushing placement, thickness of new bearings and washers to the old ones and they all match the ones removed. I am getting the same .002 measurement with or without the thrust bearing and no shim washers behind the pump or behind the output shaft bearing . I did not check the end play prior to disassemble but the clutches were toast. Any thoughts on what to look at next? Thanks
Hi Michael, thank you for watching. Here are my questions: What year is your TH350? When you first got the unit on the bench and pushed/pulled on the input shaft, about how much end play was present? What, if any, hard parts in the case did you replace? Please answer ALL of the above so I know what you may have done and recommend next steps but a priori, sounds like something's misassembled somewhere in the case; something not fully seated, etc...
@@nickstransmissionsI decipher the trans as a coming out of a 78-79 C10 with a 250 inline 6 engine. I did not check the actual end play at disassembly..there was some but I did not check actual measurement. Hard parts replaced were clutches and steels, one clutch and steel was added to the direct unit after it was machined to accept it. The trans also had a "V6" forward piston that was replaced with a V8 piston to add the additional clutch. All clearances are right at mid spec for all clutch packs. I also replaced all bushings and bearings/washers (3-4 tang). The low/reverse center support was replaced with a 700r4/4L6e "wide" unit but it has the same measurements as the one original one it replaced. Everything fits into place as it should and there is no binding, just a lack of end play.
Ok...clutches and steels are actually considered "soft parts" which i realize is odd, esp for the steels but that's how the industry classifies them. Hard parts would consist of gears, shafts, sun shell, center support, drums, apply pistons, return spring assemblies, the pump, etc. Clutch clearance wouldnt have any bearing on your end play. The hard parts you replaced are: center support and intermediate apply piston. Did this transmission have a torrington bearing on the back of the pump originally or a babbit style washer? 1978 was the first year for that torrington thrust bearing. Also, you wrote: "I am getting the same .002 measurement with or without the thrust bearing and no shim washers behind the pump" It would be impossible to have the same end play messurement with or without the pump thrust bearing installed. This situation would be easily explainable if: 1. You assembled everything correctly in the case 2. You put a bearing in place of the thrust washer that was originally on back of the pump
@nickstransmissions It had a Torrington bearing originally and that is what I replaced it with. I will try to get pics of the measurements with and without the bearing in place. I will also remove everything from the case and start over. I am becoming quiet proficient at assembly/disassembly after what seems like doing it a bazillion times lol.
Ok and that's correct for a 1978+ model year unit...And yes, we all come across particular units that just don't want to cooperate no matter what; so if nothing else, you are getting some good disassembly-assembly reps in on that transmission.
Do you do anything to prep the steels before assembly? I've read some people hit them with a red Scotchbrite pad or something. Do you have a recommendation? Thanks
Hi Ben, I will use either Scotchbrite or 400-grit sand paper to remove the glazing and any light slip marks but that's really only on a medium duty units like TH350s and 4L60Es in stock/mild performance applications...Anything else, I just purchase a full steel module, especially for HD units and newer clutch to clutch transmissions like 6L80s and their Ford and Dodge counterparts.
One more thing - check the new steels to see if they are actually flat - I found one warped new steel out of a new Ford C6 steel module last week. You can see how I found it towards the end of this video here: ruclips.net/video/gw36mf04fIQ/видео.html
Your videos are quite impressive, and I wish I had your knowledge. I am a newbie, and I am wondering if you can answer a question about air checking the pistons. how much air pressure do you use? I am building a TH350 and was checking the pump piston (intermediate apply piston I think its called) with the pump sitting on the bench by itself, and I have positive, full piston travel with 25 psi. But once I stop feeding it a constant air flow (with the rubber nozzle still held tightly against the pump air feed hole with no leaking ), then the piston slowly bleeds back down over about a 15 second period. I read that this can be normal since the piston isnt actually pushing against any clutches, but these are new lip seals. I pulled the piston and inspected the seals twice now, and there are no damaged or rolled seal lip. the piston bores are in great shape and overall the pump is in good shape.. I am a newbie. Is this normal/ok? thank you much for any advice you can give.
Hey thanks, JT P - appreciate the kind words...25-30 PSI is sufficient however don't air check that piston on the bench by itself as it needs the clutch pack installed in the case to function (and prevent the lip seal from over travelling and getting cut/damaged). This applies to any clutch pack for any unit where the clutch pack sits by itself in the transmission case. When you air check a clutch pack, you should hear and/or see strong, positive apply and compression against the apply plate with no hissing coming from the piston followed by a positive release. If you can put your hands on the clutch pack while introducing air, you should not be able to move the frictions or steels when they are fully compressed..If you can, there's a problem with the sealing integrity of that circuit and you'll have to fix it before going any further. Watch my video on the TH350 intermediate clutch if you haven't already as it covers how to set up and air check that clutch properly: ruclips.net/video/qwY0zT_aM2w/видео.html Also, please subscribe if you haven't done so - thanks again!
Hi Hiram - thanks for watching...What rattle clip? Are you referring to the anti-clunk spring that goes in between the case and center support? If so, I think I installed a case saver in that location instead but would have to watch the video again to confirm.
Hi there, so if you were to ligthly bolt that cover down to the case, and then set up a dial indicator on the input shaft, then zero and lift the input shaft, would that be the most accurate way to check this?
*** Do not bolt the pump cover /stator to the case as you may mar the working surface if you doing exactly what I show in this video *** As mentioned in the video, it's a preliminary check intended to give me a rough idea of where I'll end up once I bolt and torque the pump assembly down once everything else is back in the case (this method works for any transmission not just the Turbo 350). I want to know if I'm going to be way out (either on the high or low side of end play spec) or in the general ball pack before I install the drums/band/int clutch so I can fix it beforehand w/less disassembly if I'm too tight (given I installed that .036 shim at the rear of the case on the output ring gear). I've done enough end play checks on transmissions to know what .015, .030, etc feels like but if you haven't, I'd set up a dial indicator so you have an exact figure. I spend some time going over the things I consider for next steps based on what this preliminary check tells me... If you're wanting to see what the proper end play measuring procedure should be for the final time, check out Part 5 of this series if you haven't already: ruclips.net/video/qIiwAPqfPrg/видео.html
When you have a bleeder ball in the piston, generally speaking, there isn't one in the drum and vise versa. In real high performance applications, there may be instances where you need to drill an additional bleed port to prevent centrifugal apply in that clutch (TH350 direct drum for instance). Lastly, there may be some transmissions that have bleeder balls or valves in both piston and drum (or neither) but I can't think of any off-hand.
@@nickstransmissions so on the direct drum assembly came from a v6 th350 so most of the clutches were short one friction and steel so I swapped all the pistons to run more clutches. Now the direct drum I got one that was already machined and this one did not have a check ball compared to the one I removed. I also notice that the ball in the piston did not feed the same circuit as the one in the drum, since I’m dual feeding as long as the drum has a check ball I should be fine? I also just put the transmission together and I can’t remember if the drum had one or not, but if they all do than I can move on and if not I have to dissemble the trans to find out. Thank you for responding, I did a lot of searching and there is little info on what the check balls actually do and whether some came with or without. I hope this makes sense.
If you're using a direct drum from a V8 TH350, it should already have a bleeder ball whereas the piston from that same drum should not have a bleeder ball. But if you're using a piston that does have a bleeder ball then you have two bleed locations in the circuit which may or may not cause problems. Note - I'm assuming you meant to say 'machined piston' and not 'machined drum' as I'm not sure what you would machine on the drum itself.
@@nickstransmissions yes machined piston sorry. I will just pull it apart and check again. Thank you. I was wondering if you could do a video on case savers for the th350. I know there are three types the one piece, four piece and the bolt in with new center support, which I used because it also allows the use of wider sprag. Also how bad can a case get before you toss it.
You're welcome, man. I'll see about doing a video on case savers if the occasion arises in the near future. But as far as case condition, i generally replace them if there are signs of cracking, chips, fractures or the like. Just curious, what's your intermediate clutch clearance? Since you'll be going back into the case, figured i'd ask.
Are you referring to the converter clutch in the TH350C? If so, you'd have to see if there's a dual feed style ball capsule to replace the factory ball capsule in the snout of the input shaft. I don't do too many TH350Cs so not sure if one exists or not (or if the pre-existing factory ball capsule is a dual-feed style or not).
Hey Nick, I have a th350 with four (4) forward frictions (light duty) rather than the "standard" five (5) frictions can the piston be machined to accept the 5th plate or can I swap a piston from a five (5) friction forward clutch in to accommodate the "standard" 5th friction? This is not the direct drive drum/piston but actually the forward drum/piston. Thanks
Hi Micheal, thanks for watching...Yes, you can machine the piston - just make sure the bottom steel doesn't fit under the lugs otherwise you'll have a no-apply condition in the drum thus no forward movement.
Thank you Sir
@@nickstransmissions
Another very informative and applicable video. The direct drum bleed hole recommendation is interesting. For a street machine that sees occasional strip time and regularly shifts at 6,000 rpm, how important is it to drill this hole? Thanks again for the great content!
Hi John, thank you for the kind words!
If you're using high rate return springs and done all the other usual mods for this sort of application AND the trans is modulated AND retains its automatic forward shift pattern, a .035-.045 bleed hole should work. If you're not 100% sure, you can always install the high rate return springs and take it on a couple test passes to see if you detect either drag or centrifugal apply then make a decision from there...I'd drill it it it were mine...
Thank for the reply. I'm using a TCI full manual valve body (no trans brake). This also eliminates the auto function and modulating. I hadn't considered the high rate return springs. I do have a cut direct apply piston with a 5 clutch stack. Measuring .045 to .050" clearance with stock steels and no wave plate. I'm not sure I would be able to recognize direct clutch drag on a test. What would the signs be? What would be the consequence on a weekend only hot rod to forego the bleed hole? Thanks again fit the expert advice.
You're welcome...If going full manual trans brake, I'd add the bleed hole, especially if you're not using high rate return springs but those are strongly advised. If you're dragging you'll feel it when in 1st and 2nd and if the clutch comes on via centrifugal apply when in first, you may or may not bind or if in 2nd it will feel like a stack shift (i.e. earlier than normal/expected when considering how you have set up your governor).
I'd drill but there's no real harm in trying to see how it does without the hole and go from there assuming you install the high rate return springs. Worst case, you replace any glazed frictions and re-prep steels.
Either way, please let me know what you decide to do and what happens!
At 1:23, you said "When in 2nd gear, it will spin the drum. Do you not mean HOLD the drum?(and by default the shell/sungear)
If im talking about what happens when operating the vehicle when the shifter is in manual second then yes i mean hold the drum.
@@nickstransmissions Watch your video. Manual second or not - the one way CANNOT spin the drum because the clutches are splined to the case.
Ill watch it later today when i have time but yes the drum doesnt spin, prob a slip of the tongue when meaning to say something else. I may have been talking about the intermediate sprag rotation and its role in the transmission achiving second gear.
@@nickstransmissions That was my point. The one way's role in second gear is to stop the sun.(by way off stopping the direct, not spinning it.👍👍
Yep, I used the wrong verbiage and will note the description to avoid confusion on the part of the viewer. Thanks for catching it!
Hi Nick, I am having TH350 end play difficulty. Checking it as you do here I can not feel any...with a dial indicator and a small screw driver to pry up on the input shaft I am getting .002. I have checked and rechecked bushing placement, thickness of new bearings and washers to the old ones and they all match the ones removed. I am getting the same .002 measurement with or without the thrust bearing and no shim washers behind the pump or behind the output shaft bearing . I did not check the end play prior to disassemble but the clutches were toast. Any thoughts on what to look at next? Thanks
Hi Michael, thank you for watching. Here are my questions:
What year is your TH350?
When you first got the unit on the bench and pushed/pulled on the input shaft, about how much end play was present?
What, if any, hard parts in the case did you replace?
Please answer ALL of the above so I know what you may have done and recommend next steps but a priori, sounds like something's misassembled somewhere in the case; something not fully seated, etc...
@@nickstransmissionsI decipher the trans as a coming out of a 78-79 C10 with a 250 inline 6 engine. I did not check the actual end play at disassembly..there was some but I did not check actual measurement. Hard parts replaced were clutches and steels, one clutch and steel was added to the direct unit after it was machined to accept it. The trans also had a "V6" forward piston that was replaced with a V8 piston to add the additional clutch. All clearances are right at mid spec for all clutch packs. I also replaced all bushings and bearings/washers (3-4 tang). The low/reverse center support was replaced with a 700r4/4L6e "wide" unit but it has the same measurements as the one original one it replaced. Everything fits into place as it should and there is no binding, just a lack of end play.
Ok...clutches and steels are actually considered "soft parts" which i realize is odd, esp for the steels but that's how the industry classifies them. Hard parts would consist of gears, shafts, sun shell, center support, drums, apply pistons, return spring assemblies, the pump, etc. Clutch clearance wouldnt have any bearing on your end play. The hard parts you replaced are: center support and intermediate apply piston.
Did this transmission have a torrington bearing on the back of the pump originally or a babbit style washer? 1978 was the first year for that torrington thrust bearing.
Also, you wrote: "I am getting the same .002 measurement with or without the thrust bearing and no shim washers behind the pump"
It would be impossible to have the same end play messurement with or without the pump thrust bearing installed.
This situation would be easily explainable if:
1. You assembled everything correctly in the case
2. You put a bearing in place of the thrust washer that was originally on back of the pump
@nickstransmissions It had a Torrington bearing originally and that is what I replaced it with. I will try to get pics of the measurements with and without the bearing in place. I will also remove everything from the case and start over. I am becoming quiet proficient at assembly/disassembly after what seems like doing it a bazillion times lol.
Ok and that's correct for a 1978+ model year unit...And yes, we all come across particular units that just don't want to cooperate no matter what; so if nothing else, you are getting some good disassembly-assembly reps in on that transmission.
Do you do anything to prep the steels before assembly? I've read some people hit them with a red Scotchbrite pad or something. Do you have a recommendation? Thanks
Hi Ben, I will use either Scotchbrite or 400-grit sand paper to remove the glazing and any light slip marks but that's really only on a medium duty units like TH350s and 4L60Es in stock/mild performance applications...Anything else, I just purchase a full steel module, especially for HD units and newer clutch to clutch transmissions like 6L80s and their Ford and Dodge counterparts.
@@nickstransmissions So if the steels are new, they can go in as is? Just to clarify
No, you have to clean off all the packing grease before installation but they shouldn't require any prep work like used steels.
One more thing - check the new steels to see if they are actually flat - I found one warped new steel out of a new Ford C6 steel module last week. You can see how I found it towards the end of this video here: ruclips.net/video/gw36mf04fIQ/видео.html
@ Good call! I’ve got a small granite surface plate I can put to use.
Your videos are quite impressive, and I wish I had your knowledge. I am a newbie, and I am wondering if you can answer a question about air checking the pistons. how much air pressure do you use? I am building a TH350 and was checking the pump piston (intermediate apply piston I think its called) with the pump sitting on the bench by itself, and I have positive, full piston travel with 25 psi. But once I stop feeding it a constant air flow (with the rubber nozzle still held tightly against the pump air feed hole with no leaking ), then the piston slowly bleeds back down over about a 15 second period. I read that this can be normal since the piston isnt actually pushing against any clutches, but these are new lip seals. I pulled the piston and inspected the seals twice now, and there are no damaged or rolled seal lip. the piston bores are in great shape and overall the pump is in good shape.. I am a newbie. Is this normal/ok? thank you much for any advice you can give.
Hey thanks, JT P - appreciate the kind words...25-30 PSI is sufficient however don't air check that piston on the bench by itself as it needs the clutch pack installed in the case to function (and prevent the lip seal from over travelling and getting cut/damaged). This applies to any clutch pack for any unit where the clutch pack sits by itself in the transmission case.
When you air check a clutch pack, you should hear and/or see strong, positive apply and compression against the apply plate with no hissing coming from the piston followed by a positive release. If you can put your hands on the clutch pack while introducing air, you should not be able to move the frictions or steels when they are fully compressed..If you can, there's a problem with the sealing integrity of that circuit and you'll have to fix it before going any further.
Watch my video on the TH350 intermediate clutch if you haven't already as it covers how to set up and air check that clutch properly: ruclips.net/video/qwY0zT_aM2w/видео.html
Also, please subscribe if you haven't done so - thanks again!
What about the rattle clip?
Hi Hiram - thanks for watching...What rattle clip?
Are you referring to the anti-clunk spring that goes in between the case and center support? If so, I think I installed a case saver in that location instead but would have to watch the video again to confirm.
Hi there, so if you were to ligthly bolt that cover down to the case, and then set up a dial indicator on the input shaft, then zero and lift the input shaft, would that be the most accurate way to check this?
*** Do not bolt the pump cover /stator to the case as you may mar the working surface if you doing exactly what I show in this video ***
As mentioned in the video, it's a preliminary check intended to give me a rough idea of where I'll end up once I bolt and torque the pump assembly down once everything else is back in the case (this method works for any transmission not just the Turbo 350). I want to know if I'm going to be way out (either on the high or low side of end play spec) or in the general ball pack before I install the drums/band/int clutch so I can fix it beforehand w/less disassembly if I'm too tight (given I installed that .036 shim at the rear of the case on the output ring gear).
I've done enough end play checks on transmissions to know what .015, .030, etc feels like but if you haven't, I'd set up a dial indicator so you have an exact figure. I spend some time going over the things I consider for next steps based on what this preliminary check tells me...
If you're wanting to see what the proper end play measuring procedure should be for the final time, check out Part 5 of this series if you haven't already: ruclips.net/video/qIiwAPqfPrg/видео.html
I’ve noticed on some pistons there is another check ball, is that only for a 6cylinder apply piston compared to a v8 apply piston?
When you have a bleeder ball in the piston, generally speaking, there isn't one in the drum and vise versa. In real high performance applications, there may be instances where you need to drill an additional bleed port to prevent centrifugal apply in that clutch (TH350 direct drum for instance). Lastly, there may be some transmissions that have bleeder balls or valves in both piston and drum (or neither) but I can't think of any off-hand.
@@nickstransmissions so on the direct drum assembly came from a v6 th350 so most of the clutches were short one friction and steel so I swapped all the pistons to run more clutches. Now the direct drum I got one that was already machined and this one did not have a check ball compared to the one I removed. I also notice that the ball in the piston did not feed the same circuit as the one in the drum, since I’m dual feeding as long as the drum has a check ball I should be fine? I also just put the transmission together and I can’t remember if the drum had one or not, but if they all do than I can move on and if not I have to dissemble the trans to find out.
Thank you for responding, I did a lot of searching and there is little info on what the check balls actually do and whether some came with or without. I hope this makes sense.
If you're using a direct drum from a V8 TH350, it should already have a bleeder ball whereas the piston from that same drum should not have a bleeder ball. But if you're using a piston that does have a bleeder ball then you have two bleed locations in the circuit which may or may not cause problems.
Note - I'm assuming you meant to say 'machined piston' and not 'machined drum' as I'm not sure what you would machine on the drum itself.
@@nickstransmissions yes machined piston sorry.
I will just pull it apart and check again. Thank you.
I was wondering if you could do a video on case savers for the th350. I know there are three types the one piece, four piece and the bolt in with new center support, which I used because it also allows the use of wider sprag. Also how bad can a case get before you toss it.
You're welcome, man. I'll see about doing a video on case savers if the occasion arises in the near future. But as far as case condition, i generally replace them if there are signs of cracking, chips, fractures or the like.
Just curious, what's your intermediate clutch clearance?
Since you'll be going back into the case, figured i'd ask.
can you dual feed a lock up?
Are you referring to the converter clutch in the TH350C? If so, you'd have to see if there's a dual feed style ball capsule to replace the factory ball capsule in the snout of the input shaft. I don't do too many TH350Cs so not sure if one exists or not (or if the pre-existing factory ball capsule is a dual-feed style or not).