I swapped to a Turbo 400 transmission in my 1963 Grand Prix years ago. The original Slim Jim Rotoyhydramatic 10 died in the summer of 1998. Great Video .
I started on Toyota A20’s and A30’s as a young guy, great to see the engineering and complexity of the old designs. Looked like there was a lot to knowing the tricky disassembly process on that one. Great work, thanks for sharing.
Another great video Tom. I resealed an old cast iron Hydra-Matic that was out of a 1951 Olds last year. I seem to recall it having a different engine/trans than original. The guy I did the work (gaskets & seals) for is an old Pontiac guru that I've been doing trans work for-probably 45 years now. The Hydra-Matic had the toros, I believe the gasket kit came from Fatsco on the east coast. That son of a gun was heavy. Thanks for taking the time to make these videos. I enjoy every one of them.
You aren't quite there yet. The governor support needs to be disassembled. Underneath that you will find the sun gear damper at the end of the multiplier shaft. 9/10s of the time, these need to be replaced. In addition, if the governor housing is made of aluminum, it will need to be replaced with a steel one. Mind you, these units are car model specific. If you need to reference which housing you need, refer to the tag on the side of the transmission case. Not bad, for a first tear down. I was rebuilding these in the 1970s and everybody was terrified of the design. They are actually quite simple and a very good design, despite that they look like something from outer space. The real challenger was the dual coupling hydramatic. If you can handle a jetaway, you can easily wrap your head around this concept and design.
Thanks for the info. The housing is/was slightly worn. I was able to clean it up with a hone. Found that the teflon rings for the 4l60 reverse input drum fit nicely in that spot. Gave them the option of trying that or getting a new tail housing. They opted for the first, of course. But as of yet they have not got any of the other parts. Keep saying they are going to. We shall see. Since you have done some of these. I do have a question. The manual shows 2 sealing rings on the front of the torus cover. Mine was missing the large one. Were there instances where it did not use it?
@@CurmudgeonTransmission Hello! When I mentioned the governor housing, I meant the governor itself. Unbolt the governor from it's support and separate the output shaft from the multiplier shaft. On the end of the multiplier shaft, there is a neoprene lined cog called a sun gear damper. Often, the lining is destroyed or severely worn. These can be found on line for about $60. The governor itself, minus valves, weights and retaining rod, in other words, the housing, was originally made out of aluminum and should be replaced with a steel one. These were known for hanging up and are a tremendous ass pain to deal with if they should stick because of metal fragments. They were almost always replaced with a steel one. There will be problems with shift quality because of the fluid in common use today - aka - Dexron II. The original fluid used in these units was Dexron I, which is derived from whale oil. The only place I know of to get Dexron I anymore is O'Reilly's Autoparts and it is very expensive. Dexron I was phased out in 1974 due to outcries from environmentalists and the expensive cost of it. Five years into GM's THM-350, dealerships were sending those units out to have the case bushings changed, so that they wouldn't get eaten by the new fluid. As for your nylon ring trick/fix, it's a bad idea. They will likely expand the cavitation into the extension housing. An example of this is the GM X car citations, apollos, etc short rack steering spool valves. On cold days, power steering on these cars would quit until they warmed up. The cause of this were three nylon rings on the steering shaft spool valve that would cause grooves to wear into the rack.Once the rack cooled off, the rings would shrink back into their retaining grooves and stay there until friction from the fluid rushing past them caused them to heat up and expand back into the worn grooves they had caused from wear, hence restoring power steering. Try and find a core for oddball stuff like this. The extension housing wear from governor support rings wasn't a common issue. There are really only two week spots inside the model 10 - the torus bowl and the sun gear damper. Your torus assembly looks to be in good shape. However there are signs that it has been gone through before. The presence of permatex on the gasket between the torus cover and the bowl is a clear indicator, the missing ring and the apparent lack of permatex between the case halves, as well.. Due to the tremendous amount of pressure from the internal coupling, these transmissions were known for developing leaks everywhere. One final note, make sure you torque the torus bolts properly and in sequence. If you get a chance, please describe the symptoms that caused you to rebuild it. Thanks. Dave.
It is steel. The damper is in great shape. This is actually from another shop. According to them it was working fine but leaking everywhere. They were afraid of it. I told them I wasn't, so they sent it to me. And now here we sit waiting for them to get the parts. Been so long I'm wondering if they will. I Despise having stuff sit around forever. Inevitably something ends up getting lost.
@@CurmudgeonTransmission That is all very good news! The governor housing was likely replaced under recall, or by the shop that rebuilt the transmission. The fact that the sun gear damper is good also indicates that the overhaul was completed somewhat recently. The reason builders are frightened by these units is because of a lack of understanding how they work, and thus don't comprehend how to repair them. They are actually quite simple. There are only four clutching surfaces in the entire unit. The front clutch, the neutral clutch, the over-running band and the reverse cone. The fluid coupling fills and "unfills" for various stages of range and gear changes. When the engine starts, the coupling is filled and essentially already in first gear. The neutral clutch is also engaged, to prevent the car from moving forward while it is in first gear. Applying the reverse cone merely reverses this inclination and releases the neutral clutch. Releasing the neutral clutch and disengaging the parking pall allows the transmission to begin the first of two ranges forward in first gear. The first range is the coupling moving at a geared down pace. As the sun gear shaft (multiplier shaft) motivates the small impeller inside the torus (multiplier) and increases speed, the second range occurs by compounding the effect of the centrifugal force of the fluid inside the torus - essentially a one to one ratio inside the torus is achieved. Once this has occurred, the front clutch applies and the coupling unfills which causes such a dramatic ratio change that poorly tuned engines may stall. It also places the transmission in direct connection from the engine to the rear wheels. That is second gear. At about 15 miles per hour higher in speed, the coupling fills once again which is third gear. This is the only transmission which gets a one to one ratio by applying both first and second gear together. The over-running band is only used during kick-down. So, as you can see, quite simple and as such, an excellent concept. To set the throttle rod properly, loosen the adjuster and with the engine off, depress the gas peddle all the way to the floor and allow the throttle rod to go back as far as the peddle rod. Tighten the adjuster and take it for a spin. Minor increments in adjustment will refine the shift pattern and eventually become within tolerance. In conclusion, many of the attributes of this design are gleaned directly from the jetaway. The reverse cone, neutral clutch and internal coupling are all taken from that transmission. I hope this has been helpful and that you get as much enjoyment from these builds as I did. There are very few rebuilders still around that can rebuild these properly, and the ones that are stand to make a good deal of money. Much luck to you sir! Dave
Would possibly have a link where I could get a shift linkage kit for this same transmission ? I have a 62 grand prix 3 speed in the floor and having and issue finding the right parts.
@@CurmudgeonTransmission The parts are crazy expensive. $100 for the filter. $550 for the master kit. Only one place to get them on the east coast as far as I know.
Yeah, I was surprised. It came from another shop. They claim that it was working fine and that the customer just wanted it resealed. I don't see how that could be. They were afraid of it and convinced the customer to exchange it for a 2004R. That would not have been my choice. If it was up to me I would pick the 700R4. Told them I'm not afraid of it. Still waiting on the parts. They say they are going to get them. We'll see. Been a month now.
@@CurmudgeonTransmission Yes, I am with you on the 700 r4 I never had good luck with the 200 r4 I was wondering if the you still could get the parts. gm sure had a assortment of transmissions in my hay day as a rebuilder. I got out of the business before all of these 8 and 10 speeds came along. In fact it was 2008 when I saw the first 5 speed 5r110 that is when I went to margaritaville lol I sure enjoy watching you. It reminds me so much the way I did things. keep up the great work. 🙂
I found all of the parts and passed the info off to them. Fatsco had them all. Thinking of trying to do the same within the next couple of years. Appreciate you watching them.
I swapped to a Turbo 400 transmission in my 1963 Grand Prix years ago. The original Slim Jim Rotoyhydramatic 10 died in the summer of 1998.
Great Video .
Thanks for watching.
I started on Toyota A20’s and A30’s as a young guy, great to see the engineering and complexity of the old designs. Looked like there was a lot to knowing the tricky disassembly process on that one. Great work, thanks for sharing.
Man, been a long time since I have seen one of those. Really simple once you know what to do. Thanks for watching.
Another great video Tom. I resealed an old cast iron Hydra-Matic that was out of a 1951 Olds last year. I seem to recall it having a different engine/trans than original. The guy I did the work (gaskets & seals) for is an old Pontiac guru that I've been doing trans work for-probably 45 years now. The Hydra-Matic had the toros, I believe the gasket kit came from Fatsco on the east coast. That son of a gun was heavy. Thanks for taking the time to make these videos. I enjoy every one of them.
Thanks. Fatsco is a good source. One of the down sides of the old stuff, the weight. Thanks for watching them.
The old slim Jim! Great video!
Thanks!
Very awesome to see you working on this vintage stuff. In the days before they standardised it all and each division had their own approach.
Thanks for watching.
It is Interesting to see that they had vain style pumps back then!
I like the old stuff. I find it interesting to see some of the technology that we think is new, used way back then but never caught on.
You aren't quite there yet. The governor support needs to be disassembled. Underneath that you will find the sun gear damper at the end of the multiplier shaft. 9/10s of the time, these need to be replaced. In addition, if the governor housing is made of aluminum, it will need to be replaced with a steel one. Mind you, these units are car model specific. If you need to reference which housing you need, refer to the tag on the side of the transmission case. Not bad, for a first tear down. I was rebuilding these in the 1970s and everybody was terrified of the design. They are actually quite simple and a very good design, despite that they look like something from outer space. The real challenger was the dual coupling hydramatic. If you can handle a jetaway, you can easily wrap your head around this concept and design.
Thanks for the info. The housing is/was slightly worn. I was able to clean it up with a hone. Found that the teflon rings for the 4l60 reverse input drum fit nicely in that spot. Gave them the option of trying that or getting a new tail housing. They opted for the first, of course. But as of yet they have not got any of the other parts. Keep saying they are going to. We shall see. Since you have done some of these. I do have a question. The manual shows 2 sealing rings on the front of the torus cover. Mine was missing the large one. Were there instances where it did not use it?
@@CurmudgeonTransmission
Hello! When I mentioned the governor housing, I meant the governor itself. Unbolt the governor from it's support and separate the output shaft from the multiplier shaft. On the end of the multiplier shaft, there is a neoprene lined cog called a sun gear damper. Often, the lining is destroyed or severely worn. These can be found on line for about $60. The governor itself, minus valves, weights and retaining rod, in other words, the housing, was originally made out of aluminum and should be replaced with a steel one. These were known for hanging up and are a tremendous ass pain to deal with if they should stick because of metal fragments. They were almost always replaced with a steel one. There will be problems with shift quality because of the fluid in common use today - aka - Dexron II. The original fluid used in these units was Dexron I, which is derived from whale oil. The only place I know of to get Dexron I anymore is O'Reilly's Autoparts and it is very expensive. Dexron I was phased out in 1974 due to outcries from environmentalists and the expensive cost of it. Five years into GM's THM-350, dealerships were sending those units out to have the case bushings changed, so that they wouldn't get eaten by the new fluid.
As for your nylon ring trick/fix, it's a bad idea. They will likely expand the cavitation into the extension housing. An example of this is the GM X car citations, apollos, etc short rack steering spool valves. On cold days, power steering on these cars would quit until they warmed up. The cause of this were three nylon rings on the steering shaft spool valve that would cause grooves to wear into the rack.Once the rack cooled off, the rings would shrink back into their retaining grooves and stay there until friction from the fluid rushing past them caused them to heat up and expand back into the worn grooves they had caused from wear, hence restoring power steering.
Try and find a core for oddball stuff like this. The extension housing wear from governor support rings wasn't a common issue.
There are really only two week spots inside the model 10 - the torus bowl and the sun gear damper. Your torus assembly looks to be in good shape. However there are signs that it has been gone through before. The presence of permatex on the gasket between the torus cover and the bowl is a clear indicator, the missing ring and the apparent lack of permatex between the case halves, as well.. Due to the tremendous amount of pressure from the internal coupling, these transmissions were known for developing leaks everywhere. One final note, make sure you torque the torus bolts properly and in sequence. If you get a chance, please describe the symptoms that caused you to rebuild it.
Thanks. Dave.
It is steel. The damper is in great shape. This is actually from another shop. According to them it was working fine but leaking everywhere. They were afraid of it. I told them I wasn't, so they sent it to me. And now here we sit waiting for them to get the parts. Been so long I'm wondering if they will. I Despise having stuff sit around forever. Inevitably something ends up getting lost.
@@CurmudgeonTransmission
That is all very good news! The governor housing was likely replaced under recall, or by the shop that rebuilt the transmission. The fact that the sun gear damper is good also indicates that the overhaul was completed somewhat recently.
The reason builders are frightened by these units is because of a lack of understanding how they work, and thus don't comprehend how to repair them.
They are actually quite simple. There are only four clutching surfaces in the entire unit. The front clutch, the neutral clutch, the over-running band and the reverse cone. The fluid coupling fills and "unfills" for various stages of range and gear changes. When the engine starts, the coupling is filled and essentially already in first gear. The neutral clutch is also engaged, to prevent the car from moving forward while it is in first gear. Applying the reverse cone merely reverses this inclination and releases the neutral clutch. Releasing the neutral clutch and disengaging the parking pall allows the transmission to begin the first of two ranges forward in first gear. The first range is the coupling moving at a geared down pace. As the sun gear shaft (multiplier shaft) motivates the small impeller inside the torus (multiplier) and increases speed, the second range occurs by compounding the effect of the centrifugal force of the fluid inside the torus - essentially a one to one ratio inside the torus is achieved. Once this has occurred, the front clutch applies and the coupling unfills which causes such a dramatic ratio change that poorly tuned engines may stall. It also places the transmission in direct connection from the engine to the rear wheels. That is second gear. At about 15 miles per hour higher in speed, the coupling fills once again which is third gear. This is the only transmission which gets a one to one ratio by applying both first and second gear together. The over-running band is only used during kick-down.
So, as you can see, quite simple and as such, an excellent concept.
To set the throttle rod properly, loosen the adjuster and with the engine off, depress the gas peddle all the way to the floor and allow the throttle rod to go back as far as the peddle rod. Tighten the adjuster and take it for a spin. Minor increments in adjustment will refine the shift pattern and eventually become within tolerance. In conclusion, many of the attributes of this design are gleaned directly from the jetaway. The reverse cone, neutral clutch and internal coupling are all taken from that transmission.
I hope this has been helpful and that you get as much enjoyment from these builds as I did. There are very few rebuilders still around that can rebuild these properly, and the ones that are stand to make a good deal of money. Much luck to you sir!
Dave
@@davedorsey1213 Thanks for all the tips.
There are two variations of the RHM375. Roto 10 and Roto 5.
Yes. I state that in the video. Thanks for watching.
Would possibly have a link where I could get a shift linkage kit for this same transmission ? I have a 62 grand prix 3 speed in the floor and having and issue finding the right parts.
Try Fatsco, link in the description. Or Charlie Tranny, charlietranny.com/375RHM.htm Possibly these guys also, ttps://www.restorationhydramatics.com
@@CurmudgeonTransmission Thank you.
Do you have a reassembly of this Roto 10?
No, not yet. They keep telling me they are going to get the parts. Been cleaned up and ready to go for about 3 months now.
@@CurmudgeonTransmission The parts are crazy expensive. $100 for the filter. $550 for the master kit. Only one place to get them on the east coast as far as I know.
@KeggyUran Yeah. I assume you are talking about Fatsco. They have it all. Just can't get the shop we are doing it for to buy it.
looks pretty good for being 62 years old. So what was the customers concern the governor rings if were leaking it might not start in 1st. just curious
Yeah, I was surprised. It came from another shop. They claim that it was working fine and that the customer just wanted it resealed. I don't see how that could be. They were afraid of it and convinced the customer to exchange it for a 2004R. That would not have been my choice. If it was up to me I would pick the 700R4. Told them I'm not afraid of it. Still waiting on the parts. They say they are going to get them. We'll see. Been a month now.
@@CurmudgeonTransmission Yes, I am with you on the 700 r4 I never had good luck with the 200 r4 I was wondering if the you still could get the parts. gm sure had a assortment of transmissions in my hay day as a rebuilder. I got out of the business before all of these 8 and 10 speeds came along. In fact it was 2008 when I saw the first 5 speed 5r110 that is when I went to margaritaville lol I sure enjoy watching you. It reminds me so much the way I did things. keep up the great work. 🙂
I found all of the parts and passed the info off to them. Fatsco had them all. Thinking of trying to do the same within the next couple of years. Appreciate you watching them.