Hey there,

I'm researching options I may have with my transmission, so any advice or actual experience will be welcomed.

My '61 Bonneville is a street cruiser, with an early ('59) recently rebuilt 389 (.030" over, so 400ci). It is fitted with either THE original or AN original Hydramatic (Serial #P-60-200684), which I find to be a nice transmission. Unfortunately it doesn't stand up to the torque under hard acceleration (slips), so I feel I will need to do something with it at some stage. It has been serviced, so I presume wear and tear is probably the issue. I've attached  photos of the ID plate and pan, so hopefully someone will be able to accurately identify it for me?

What I understand is:-

* This transmission is ridiculously expensive to rebuild (I'm in Australia), and parts are scarce. Shame really, as I would be happy to just rebuild what I have.

* TH350 & TH400's, whilst good transmissions, are heavy on fuel and use significant horsepower to run

* TH700r4 is a great choice, as it has an overdrive that is mechanical therefore relatively easy to set up (unlike the 4L60E, which is electronic)

How am I doing so far?

 

 

I would not fear a 4L60E - it can operate with an aftermarket transmission control module.  And it can be built / rebuilt to handle the power and torque.  Though I'm not sure about the bolt pattern relationship to your engine.

Rick

I think your stuck with the Hydromatic as I believe your starter is mounted to the trans and NOT the block. My 421 was built in the 1st week of 1964 and is one of the very 1st with the starter on the block.  I have the choice of any trans, but went with the 200R4 for the overdrive and gas saving's.  Take a look at your starter. In racing circles the 2 spd Hydro is still very sought after and can be rebuilt darn near bulletproof.

Edited November 1, 20241 yr by JUSTA6

I agree with Justa. Assuming you don't have a starter issue, I recommend the 200 4R over 700 R4 simply because it will bolt up to the Pontiac engine with no need for an adaptor kit. The 200 is 2 inches longer than a 400. So you will have to move or custom make your trans cross member. Also the added 2 inches means shortening the driveshaft. 200s can manage the torque of your engine with the right rebuild plus you now have overdrive. A more modern transmission like a 4L60 or 4L80 or better may require modifications to the transmission tunnel and/or floor pan to make room for it. 

Edited November 1, 20241 yr by Frosty

I'm somewhat biased on this - I LOVE my TH400. Smooth & strong. I THINK there's an adaptor kit to mate a TH400 to your block. Sapping horsepower? Really? How many tenths of a second did you want to save? Overdrive would be nice but do you plan any major trips?

All these modern niceities (disc brakes are another example) are great but unless you're doing big miles I can't see why you'd bother.

Of course if you had a Corolla, the money you saved on car repairs would enable you to bathe in ass's milk and then quaff French champagne and gobble lobster for breakfast every day.

2 hours ago, Fitzy said:

I'm somewhat biased on this - I LOVE my TH400. Smooth & strong. I THINK there's an adaptor kit to mate a TH400 to your block. Sapping horsepower? Really? How many tenths of a second did you want to save? Overdrive would be nice but do you plan any major trips?

All these modern niceities (disc brakes are another example) are great but unless you're doing big miles I can't see why you'd bother.

Of course if you had a Corolla, the money you saved on car repairs would enable you to bathe in ass's milk and then quaff French champagne and gobble lobster for breakfast every day.

True the HP issue probably isn't a major concern for me, however we do almost 10,000miles pa (½ on the M1) so the overdrive I definitely a consideration 🤙

11 hours ago, Frosty said:

I agree with Justa. Assuming you don't have a starter issue, I recommend the 200 4R over 700 R4 simply because it will bolt up to the Pontiac engine with no need for an adaptor kit. The 200 is 2 inches longer than a 400. So you will have to move or custom make your trans cross member. Also the added 2 inches means shortening the driveshaft. 200s can manage the torque of your engine with the right rebuild plus you now have overdrive. A more modern transmission like a 4L60 or 4L80 or better may require modifications to the transmission tunnel and/or floor pan to make room for it. 

I like the sound of that - simple! My driveshaft will need a balance anyway, so what better time to do that than after shortening it?

The starter issue has me a bit concerned though🤔

11 hours ago, JUSTA6 said:

I think your stuck with the Hydromatic as I believe your starter is mounted to the trans and NOT the block. My 421 was built in the 1st week of 1964 and is one of the very 1st with the starter on the block.  I have the choice of any trans, but went with the 200R4 for the overdrive and gas saving's.  Take a look at your starter. In racing circles the 2 spd Hydro is still very sought after and can be rebuilt darn near bulletproof.

I'm not so worried about the strength of the transmission after building, but the cost of rebuilding 😬

More Useless Trivia..???

Just in case anyone is curious...The transmission ID plate indicates..

Hydramatic..(different from the Roto-Hydramatic...Commonly Known as "slim jim")

P = Standard 2bbl. Installation.. 

60 = Year of MFG..

200684 = Sequential number.. 

Tri-power and Super Duty Hydramatic cars Have a Different Prefix Code...   Police/Taxi and Ambulance also Have their own unique Prefix Code...

TLBT..

JUSTA coupla questions...

I may be able to access (from a reliable source) a T700 that has been rebuilt with a Stage 2 shift kit. Also has a manual kick down.

1. Would this be a good option for me?

2. How much work (ie: cost!) would be involved in fitting it to my car (adapter, transmission mounting, driveshaft mods, geasrshift/indictor changes, etc?)?

3. Are there any reasons to avoid this option that I should be aware of?

Paul 

I am with justA here 

your block doesn’t have the metal to drill to mount a starter too. Your starter is mounted to the trans . 
soo… any trans swap will require a adaptor kit for starter mounting 

I looked at this when deciding what to do with my original trans , it all sounds great but lots of $$$$ to do a swap .

i decided to have my trans rebuilt $3800 nzd and it’s great !!! Doesn’t leak , shift nice and no mucking around with any of the linkages , mounts . Speedo drive . Drive shaft , coolant lines , 

I call it kiss 

keep 

it 

simple 

stupid 

Bonne61..

Kiwi and Justa or is it Justa and Kiwi...?? Are right on point...The Starter mounts to the Bellhousing and there is No real viable way Around that...Pre 1964 Pontiac engine Blocks Do Not have a place and or a provision to drill holes in the engine block to mount the starter..

Although there may be or may not be a way to modify a modern TH 350/400..700R4/200R4...Etc...Case/Bellhousing to accept The old school Transmission mounted starter...

If there some sort of an Adapter kit to Do that...It is Completely Unknown to Me...

TLBT...

Edited November 2, 20241 yr by TWO LANE BLACK TOP

2 hours ago, 64 kiwi boni said:

Paul 

I am with justA here 

your block doesn’t have the metal to drill to mount a starter too. Your starter is mounted to the trans . 
soo… any trans swap will require a adaptor kit for starter mounting 

I looked at this when deciding what to do with my original trans , it all sounds great but lots of $$$$ to do a swap .

i decided to have my trans rebuilt $3800 nzd and it’s great !!! Doesn’t leak , shift nice and no mucking around with any of the linkages , mounts . Speedo drive . Drive shaft , coolant lines , 

I call it kiss 

keep 

it 

simple 

stupid 

That sounds good & was my first & ideal solution, as I'm happy with the Hydramatic.

But...I'm told parts are rare and expensive, and the rebuild could cost me up to $8000. 

So this may be simple, but it's also stupid IMO?

You know, Paul - have you had a specialist inspect it? Slippage MIGHT be a band adjustment or something simple. Those old autos were robust and without abuse should last for decades.

3 hours ago, Bonne61 said:

That sounds good & was my first & ideal solution, as I'm happy with the Hydramatic.

But...I'm told parts are rare and expensive, and the rebuild could cost me up to $8000. 

So this may be simple, but it's also stupid IMO?

Paul if you can’t find  some one to fix it , I have my mate here who can rebuild it for you 

it would just cost you shipping to get it to nz 

1 hour ago, Fitzy said:

You know, Paul - have you had a specialist inspect it? Slippage MIGHT be a band adjustment or something simple. Those old autos were robust and without abuse should last for decades.

I would bet it needs a rebuild , I don’t beleave there is any adjustments in these hydromatics 

1 hour ago, 64 kiwi boni said:

Paul if you can’t find  some one to fix it , I have my mate here who can rebuild it for you 

it would just cost you shipping to get it to nz 

I would bet it needs a rebuild , I don’t beleave there is any adjustments in these hydromatics 

I've had it serviced (new oil, filter and adjusted) when the engine was rebuilt, and also recently. It works fine atm, unless I stand on it hard from the bottom then it slips pretty bad (over 420ft/lb torque allegedly, so no surprises really).

I just want to know my options so I'm not left with a broken car & no idea of the next step.

Thanks for the info - if I can get an idea of what your mate would charge it may give me another option.

2 hours ago, Fitzy said:

You know, Paul - have you had a specialist inspect it? Slippage MIGHT be a band adjustment or something simple. Those old autos were robust and without abuse should last for decades.

Given the ID plate on it, my bet is it's already lasted for decades 😆

it would be the same as mine $3800nzd

Edited November 3, 20241 yr by 64 kiwi boni

Bonne61...

This is Probably a stupid question...But I'm going to ask Anyway...Have you checked the Transmission Fluid Level..??

With the car in Park with the Engine running and warmed up to Normal Operating Temperature ...Sitting on level ground...??

The reason I ask this question...Is because those Old style Hydramatic transmissions are very Sensitive to the fluid levels..To the point...That even if it is slightly low..It can Cause slipping and erratic Shifting...If the level is slightly High It can cause the trans fluid to foam up...And cause slipping and erratic shifting and overheating of the Fluid...Those transmissions Required Type A Fluid...I'm not sure if the Modern GM Dexron 2 fluid still has the same properties as the Type A fluid...That might be something to take a hard look at...Before dropping a lot of cash into a Rebuild....

TLBT..

 

1 hour ago, 64 kiwi boni said:

it would be the same as mine $3800nzd

Thank you kind sir!

1 hour ago, TWO LANE BLACK TOP said:

Bonne61...

This is Probably a stupid question...But I'm going to ask Anyway...Have you checked the Transmission Fluid Level..??

With the car in Park with the Engine running and warmed up to Normal Operating Temperature ...Sitting on level ground...??

The reason I ask this question...Is because those Old style Hydramatic transmissions are very Sensitive to the fluid levels..To the point...That even if it is slightly low..It can Cause slipping and erratic Shifting...If the level is slightly High It can cause the trans fluid to foam up...And cause slipping and erratic shifting and overheating of the Fluid...Those transmissions Required Type A Fluid...I'm not sure if the Modern GM Dexron 2 fluid still has the same properties as the Type A fluid...That might be something to take a hard look at...Before dropping a lot of cash into a Rebuild....

TLBT..

 

Thanks for that - the level is absolutely correct, and I have experienced it worsening when the level was low.

I'll do some investigation into the ATF, but you'd expect the replacement product to be "reverse" suitable (I'd hope, anyway).

1 hour ago, TWO LANE BLACK TOP said:

Bonne61...

This is Probably a stupid question...But I'm going to ask Anyway...Have you checked the Transmission Fluid Level..??

With the car in Park with the Engine running and warmed up to Normal Operating Temperature ...Sitting on level ground...??

The reason I ask this question...Is because those Old style Hydramatic transmissions are very Sensitive to the fluid levels..To the point...That even if it is slightly low..It can Cause slipping and erratic Shifting...If the level is slightly High It can cause the trans fluid to foam up...And cause slipping and erratic shifting and overheating of the Fluid...Those transmissions Required Type A Fluid...I'm not sure if the Modern GM Dexron 2 fluid still has the same properties as the Type A fluid...That might be something to take a hard look at...Before dropping a lot of cash into a Rebuild....

TLBT..

 

Just found this - thought it might be useful?

Type A ATF History And Compatibility

The “Type A, Suffix A” specification replaced Type “A” in the late 1950's. Dexron “B” fluidlater replaced Type A, Suffix A. All iterations of Dexron B, Dexron II and Dexron III ATF products are backward compatible with Type A and Type A , Suffix A fluids.

I'm using Penrite DX-111, so that should be right?

tps://www.bing.com/search?pglt=43&q=1961+Hydromatic+transmission+rebuild+kit&cvid=2afcbf44bc174ed4bd64cee7ff41fc15&gs_lcrp=EgRlZGdlKgYIABBFGDkyBggAEEUYOTIGCAEQABhAMgYIAhAAGEAyBggDEAAYQDIGCAQQABhAMgYIBRAAGEAyBggGEAAYQDIGCAcQABhAMgYICBAAGEDSAQk0NjI2OGowajGoAgCwAgA&FORM=ANNTA1&adppc=EDGEDSP&PC=EDGEDSE

Search showing many options.  Will click the fatsco link and send that too.  It also states that kit was used for Holdens as well so shouldn't be that much of a prob to find someone to work on it. Fatsco has tech info line which could help.  Might be cheaper for you to buy kit and have someone install.  Good Luck

https://www.fatsco.net/online-store/1961-1963-Roto-5-Hydramatic-Rebuilding-Kits-p51573015

https://www.bing.com/shop?q=1961 Hydromatic transmission rebuild kit&FORM=SSAT01&cvid=2afcbf44bc174ed4bd64cee7ff41fc15&originIGUID=536866BC0AD64839AF2C1E16A166A5D6

 

Edited November 3, 20241 yr by JUSTA6

7 hours ago, JUSTA6 said:

tps://www.bing.com/search?pglt=43&q=1961+Hydromatic+transmission+rebuild+kit&cvid=2afcbf44bc174ed4bd64cee7ff41fc15&gs_lcrp=EgRlZGdlKgYIABBFGDkyBggAEEUYOTIGCAEQABhAMgYIAhAAGEAyBggDEAAYQDIGCAQQABhAMgYIBRAAGEAyBggGEAAYQDIGCAcQABhAMgYICBAAGEDSAQk0NjI2OGowajGoAgCwAgA&FORM=ANNTA1&adppc=EDGEDSP&PC=EDGEDSE

Search showing many options.  Will click the fatsco link and send that too.  It also states that kit was used for Holdens as well so shouldn't be that much of a prob to find someone to work on it. Fatsco has tech info line which could help.  Might be cheaper for you to buy kit and have someone install.  Good Luck

https://www.fatsco.net/online-store/1961-1963-Roto-5-Hydramatic-Rebuilding-Kits-p51573015

https://www.bing.com/shop?q=1961 Hydromatic transmission rebuild kit&FORM=SSAT01&cvid=2afcbf44bc174ed4bd64cee7ff41fc15&originIGUID=536866BC0AD64839AF2C1E16A166A5D6

 

Thank you.

15 hours ago, JUSTA6 said:

tps://www.bing.com/search?pglt=43&q=1961+Hydromatic+transmission+rebuild+kit&cvid=2afcbf44bc174ed4bd64cee7ff41fc15&gs_lcrp=EgRlZGdlKgYIABBFGDkyBggAEEUYOTIGCAEQABhAMgYIAhAAGEAyBggDEAAYQDIGCAQQABhAMgYIBRAAGEAyBggGEAAYQDIGCAcQABhAMgYICBAAGEDSAQk0NjI2OGowajGoAgCwAgA&FORM=ANNTA1&adppc=EDGEDSP&PC=EDGEDSE

Search showing many options.  Will click the fatsco link and send that too.  It also states that kit was used for Holdens as well so shouldn't be that much of a prob to find someone to work on it. Fatsco has tech info line which could help.  Might be cheaper for you to buy kit and have someone install.  Good Luck

https://www.fatsco.net/online-store/1961-1963-Roto-5-Hydramatic-Rebuilding-Kits-p51573015

https://www.bing.com/shop?q=1961 Hydromatic transmission rebuild kit&FORM=SSAT01&cvid=2afcbf44bc174ed4bd64cee7ff41fc15&originIGUID=536866BC0AD64839AF2C1E16A166A5D6

 

Hey there,

It appears as if all of those links are JUSTA for Roto-Hydramatics. Very little for mine (apart from a few scattered components.

Mine is a P-60 ('60 model) Super Hydra-Matic (earlier known as a Controlled Coupling HydraMatic). It's a 4 speed auto. not a Roto-, not a Turbo-

I've been told I can run Ford Type F grade atf in it to try to reduce the slipimprove things - any of you guys heard of that?

1 hour ago, Bonne61 said:

Hey there,

It appears as if all of those links are JUSTA for Roto-Hydramatics. Very little for mine (apart from a few scattered components.

Mine is a P-60 ('60 model) Super Hydra-Matic (earlier known as a Controlled Coupling HydraMatic). It's a 4 speed auto. not a Roto-, not a Turbo-

I've been told I can run Ford Type F grade atf in it to try to reduce the slipimprove things - any of you guys heard of that?

Correct Paul 

yours is a

super hydromatic like the one in my 64 

they are a 4 speed and my trans is running dextron 3 

not sure about using anything ford !!!!!

that's justA asking for trouble 

Something to look at … what colour is your fluid and how does it smell ? That will tell you lots about those bands that are slipping 

You know that the word "Ford" is an acronym.  Maybe you have heard of this version, maybe not.

FORD (backwards)  -  Driver Returns On Foot

Rick

 

3 hours ago, 64 kiwi boni said:

Correct Paul 

yours is a

super hydromatic like the one in my 64 

they are a 4 speed and my trans is running dextron 3 

not sure about using anything ford !!!!!

that's justA asking for trouble 

Something to look at … what colour is your fluid and how does it smell ? That will tell you lots about those bands that are slipping 

Yes, I was thinking the Ford fluid wasn't a good idea. I did get to the bottom of the advice though - short answer is, the Type F has properties (it's stickier) that make the gears hold on longer, than change quicker. So if you like the effect you'll argue it's like a "shift kit" effect. If you don't, you'll say it's a harsher change. Evidently popular many years ago in racing circles. So more of an urban myth than a scientifically researched truth, with no definitive information on what it may do to seals/bands, etc over the long term.

The fluid is pretty much the same colour as it was when came from the container. It doesn't slip at all times though, only when I flog it. So not often, to be fair. There than that, it shifts quite well. Does hang onto second a bit when it's cold, but presumably that's valve body wear (to be expected)?

I have no desire to change it, but want to be prepared in the event of a failure. However, it seems the issue is a big one...

Rebuilding will cost a packet, a t350/400 won't be ideal (3 speed), a t700 seems to require a fair bit of work to fit up. The 200r seems the best option if I swap, but again a bit of work plus they're not that common over here either. I can buy built ones from the US, but then there's the cost issue again. I have found that Butler have an adapter plate that allows me to run my starter with a Chev pattern brand though, so that's promising.

The future is not yet clear, but I'm glad I've started the research now & not when I'm desperate for a solution 😀

10 hours ago, B52bombardier1 said:

You know that the word "Ford" is an acronym.  Maybe you have heard of this version, maybe not.

FORD (backwards)  -  Driver Returns On Foot

Rick

 

i thoought it was 

fix or repair daily