Hydramatic vs diff Trans

[Chicken Coupe]

 So I have a hydramatic 315 out of a 60 CDV.  I was quoted 2500.00 to rebuild.  A few questions. 

1.Is this a fair price or at least average price?
2. Whats the pros and cons of keeping the hydramatic. vs 700r4 or th400.
3. If I go to a diff trans. What models have worked for others?  th400,700r4,4l60e,  Would these work with the stock 2.94 rear-end?

Thank you for your time.

[bcroe]

So I have a hydramatic 315 out of a 60 CDV.  I was quoted 2500.00 to rebuild.  A few questions. 

1.Is this a fair price or at least average price?
2. Whats the pros and cons of keeping the hydramatic. vs 700r4 or th400.
3. If I go to a diff trans. What models have worked for others?  th400,700r4,4l60e,  Would these work with the stock 2.94 rear-end

I drove the old hydro for 1/3 million miles, and often
wished I had a stick 4 speed instead.  Problems with
performance, reliability, and service.  BUT it was
not swapped for a later, torque converter trans,
because the conversion would be so difficult. 

Your axle ratio would work well with any 3 speed
(TH400), a somewhat higher number might be ideal
with a 4 speed.  BUT..
The Hydro has a completely different shift
pattern, which also involves a neutral switch. 
The drive shaft will need some custom work.  The
bell housings are completely different, and
with no torque converter holes on the flywheel,
there may be a problem with a centering hole
for the converter.  Mounts are different.  Some
electric controls and different throttle
connections are needed.  The conversions I
hear about often solved a lot of problems by
swapping the engine and trans.  good luck,
Bruce Roe

[jwwseville60]

By 1960, the Hydramatic had matured into a very solid tranny. (Opinions please).
Rolls Royce used it until 1965.

If it were my CDV, I would stick with the original or go with a 4 or 5-speed manual.
Be advised the 4L60e tranny has electronics to contend with.

[Chicken Coupe]

 I appreciate all the answers.  I definitely want automatic.    I also know about all the adaptors and modifications to get  th400 ,700r4,4l60e,etc.

IM just trying to get feedback from people who have actually swapped it and to tell me if they are happy or regret the swap.    But please do keep the comments coming. 

[Jay Friedman]

By 1960, the Hydramatic had matured into a very solid tranny. (Opinions please).
Rolls Royce used it until 1965.

If it were my CDV, I would stick with the original or go with a 4 or 5-speed manual.
Be advised the 4L60e tranny has electronics to contend with.

I think the Hydramatic used by Rolls Royce until 1965 was the 1952-55 version, not the 56 or later version.

[Bob Kielar]

Have you checked with the Modified Chapter someone there might have attempted this? Just a thought.
Keep Cruzin,
Bob Kielar

[Chicken Coupe]

 What's the modified chapter?

[J. Gomez]

What's the modified chapter?

Brian,

The Cadillac and LaSalles modified chapter. 

http://www.modifiedcadillac.org/

[Roger Zimmermann]

I think the Hydramatic used by Rolls Royce until 1965 was the 1952-55 version, not the 56 or later version.

That's correct, Jay!

[Roger Zimmermann]

So I have a hydramatic 315 out of a 60 CDV.  I was quoted 2500.00 to rebuild.  A few questions. 

1.Is this a fair price or at least average price?

When I'm overhauling that kind of transmission, I'm asking about $ 1500, work and parts. But I'm not an enterprise, I'm doing that with the mind of helping people, not getting rich. I have about 40 hours for a transmission and I'm asking $ 650 for my work. It's a tad more than $ 16 per hour...
If the work is well done, the price you got is a good one. I just hope for you that the shop is knowing those trannies.
I cannot answer your other questions.

[Caddy Wizard]

If you are going to use a modern Chevy transmission in an old Cadillac, the 700R4 is probably the way to go.  It is reliable, smooth, and has a 30% overdrive ratio 4th gear.  So it will let the engine cruise on the highway at low revs and will give the best fuel economy. 


The 4L60E has an electronic control module, instead of a mechanical valve body, to control the shifting.  That might be more hassle than you want.

[TJ Hopland]

315 engine in a 60?  Or a 390?  Either way it looks like adapters are not a problem.

https://transmissionadapters.com/collections/cadillac

Its the rest that I think will get even more expensive as you go.

[dinhnguyen57]

I just had my transmission rebuilt for my '59 at a cost of $4400 in the San Francisco Bay Area, a couple months ago.  There was another local guy who wanted me to remove the transmission and deliver it to him to rebuild. I would have to install it myself, afterwards.  He wanted $5000.  I few out-of-state placed wanted me to ship them my transmission and the rebuild would be $3000.  Shipping would be $600.  It's harder and harder to find mechanics who are willing to work on these transmissions.  I asked why so much and my mechanic said the bell housing part alone was $600, ordered from a place in New Jersey.

[35-709]

If you are going to use a modern Chevy transmission in an old Cadillac, the 700R4 is probably the way to go.  It is reliable, smooth, and has a 30% overdrive ratio 4th gear.  So it will let the engine cruise on the highway at low revs and will give the best fuel economy.


The 4L60E has an electronic control module, instead of a mechanical valve body, to control the shifting.  That might be more hassle than you want.

I agree that with the 2:94 rear ratio a TH400 is the best option for a replacement.  IMO, you would want a 3:55 or higher for the 700R4/4L60.  Having said that, at $2500 having your Hydramatic rebuilt is the most economical way to go at today's prices and they are a good transmission. 

[Roger Zimmermann]

315 engine in a 60?  Or a 390?  Either way it looks like adapters are not a problem.

315 was the type of transmission, not the engine!

[Roger Zimmermann]

Brian, you are faced now with two solutions: either rebuild your transmission (why don't you try yourself?) or use another transmission with all the costs involved. In both cases, the job will not be done in 5 days and the transplant may be more expensive as at first glance.
Anyway, it's your car and you do with it what you want...On the other side, don't be afraid by the complexity of that transmission: a friend of mine without transmission knowledge rebuild his '56 Hydramatic with success...Just take your time, do a lot of pictures, note which washer is going where and so on. You will succeed, at a fraction of the costs from an outside shop without experience or a transplant.

[bcroe]

I managed to teach myself to rebuild a TH400 in
6 weeks, carefully studying the manual and doing
it several times.  But this might be the easiest
trans possible, a hydro is a challenge.  A few
tools, possibly home made, help a lot. 

Any trans you put in will move the car, but for
optimum launch, high speed cruising, and economy,
the axle ratio needs to match.  In my opinion,
for a 3 speed the axle should be in the range of
2.4 to 2.9 to 1.  I manage to get excellant overall
performance with similar weight and power, from a
switch pitch TH400 and 2.41:1.  The 400 is also by
far the STRONGEST, cheapest, and possibly the simplest. 

A 4 speed might give a bit better mileage, but
needs an axle ratio well into the 3s to properly
use the overdrive gear.  I do not care to have
any of those mentioned in a powerful, heavy car,
they would soon break in my service.  They are
expensive and more difficult to set up, and not
as smooth as my electronically controlled switch
pitch.  good luck, Bruce Roe

[Dave Shepherd]

Good advice and info, Bruce, especially  about the gear ratio required to utilize the o/d trans. Had a modified car in my shop last  year 700r4 and 3.08 gearing, would constantly  down shift out of 4th even on the slightest  grade, we put in 3.55 gears and it was easier to drive.

[Chicken Coupe]

I thank all of you for your input.    I am pulling motor and trans  to get body off frame resto so I will have plenty of time to decide on trans.     Maybe I will get froggy and attempt the trans myself.   Installing this trans or any other trans with mods is not an issue.  Its just price and what's the best route.

I understand the builder in mind works on Classic roll Royces.   I will take the book up there and verify he does have the tools if I decide to have them rebuild it.

[fishnjim]

I think $2500 is more than fair.   I had that in parts alone, a few years back, and mine still leaks.   I'd be more concerned on how well this guy does work and if it's guaranteed.  It's a major pain to yank them in and out and do it over.  And almost no way cheap to check before mated back to a running engine.   And if U never did one, the chances of getting it right the first time are diminished.  Personally, I won't mess with them but does put me at a disadvantage when things go wrong.
Another option, find a good used one. 
You'll easily eat that much and more doing a swop and takes some engineering to boot.  Most of the swops are for later models where the bell housing bolts up of adapts easily and only the drive shaft needs to be length adjusted and/or a gear swop in the rear end.
If you want a better option. like someone mentioned, change the motor and trans to a modern one, like a LS or something dependable with FI for todays crappy fuels.  With body off, you have plenty of room to fabricate the mounts, etc. but won't be cheap either, depends on how the motor and trans if obtained.