Technical GM TH 250 trans

Due to some problems with my clutch knee and having issues moving around in a small truck cab it might be time for a automatic trans in my 37 Chevy truck. I am wanting a small trans so there will be minimal modifications needed to be done to the floor so that weak TH 250 trans popped in my mind,can they be made to be a little tougher and are there any parts still available. It will be going behind a 235 that might put out 120 hp.

 

They can be upgraded.

Some bracket race dragster guys have a fetish for them.

 

Don't overlook the grand old aluminum Powerglide. Machine the clutch piston to accept a couple more disks, add a hardened input shaft, Trans-go shift, kit becomes a real contender.

 

T200 is very small and will more than handle that 235. I wish I had used one in my car. Very compact.

 

My left knee is making me ponder the wisdom of running the 5 speed behind the 292 in my 48.

 

Well, if ya had one, use it
If I was trans shopping I’d probably look at a 200r4
I never liked a PG for regular driving.
But an adapter will be needed for a newer auto.
If ya find a th250c ya got a lock up converter which kinda acts like a poor man’s overdrive

 

I put 200R4 in all the cars I have built in the past several years.

 

I haven’t used one …..yet
But will if I need an OD without a controller.
Considering one in the wife’s 56

 

Aren’t they a torque tube? So you’re going to need a fair bit more work than just a trans swap. In which case might be worth looking at rear axle ratios and transmission ratios and see what’ll work with your 235.

 

Put a 200R4 in my '53 king cab behind a warm 235. Used a commercial adaptor plate/flywheel (Chevs of the 40s? Can't remember who's). Worked like a champ. They are very easy to rebuild.

 

My 37 has a T-5 in so no torque tube,I do not have that trans yet and just getting in the planning stages of this swap but a guy at work has some. I have access to a used adapter kit to put a modern trans on a 235 but will have to come up with side mounts but I think that will be easy,it presently has a 57 235 but it has issues so I have a 60 235 on the stand that has provisions for side mounts. My 65 Custom 500 is also going to get a automatic swap as it has a very stiff clutch,hate to give up on the manuals but my body is saying it needs to happen.

 

I made side mounts for my '53 pickup using 3/8" plate. They screw to the adaptor with countersunk 3/8" flat head bolts from the transmission side of the plate. I used old Ford type rubber donut engine mounts on the frame.

 

I really enjoy the auto in my Mercury. You just drive them differently.

 

^^^^ simple and practical. Circle Track suppliers also sell ones that bolt to the back side of the trans and also use Ford engine donuts.

 

350 turbo is a good all around automatic...

 

Save yourself some grief and just go with a 350.

 

with both knees worn out from 50 years of fixing cars in dealership shops.skiing hard and kick starting a pan head , i can attest that we can still drive sticks with replacement knees guys, yes it will take a few painful months of PT but that pain is worth it,

 

Drove trucks for 40 plus years, jumped down from flatbed trailers unloading, fell off trailers while unloading and had dust ups off dirt bikes when silly enough to get on them and at 67 year old still would have nothing but a manual gearbox. Knee pain is why they invented painkillers.

 

I have a T350 in my '37 truck, the firewall and floor were cut up when I purchased the truck so I can't say for sure how much I've modified it to fit the 250 and T350. I happy with it, truck has a 3.08 rear axle and 28" tall tires, it runs 70 mph all day long with ease. I have a hump in the floor for clearance that does move the throttle over so foot space is tight, had I lowered the trans a bit I could have minimized the transmission tunnel. I use a Lokar floor shift mounted to the rear of the transmission.

 

Just trying to find the smallest trans so there will. be minimal cutting so does anyone know just how much larger a 350 is from the 250. It's more then just the knees,there is also damage from a car wreck 45 years ago that is limiting my movement in that very small cab. The last time I messed with one of those trans I could lift it in the car without a jack but that's been 30 years ago.

 

A 250 and 350 are exactly the same size.
A 250 is just a 350 that has an intermediate band instead of clutches for 2nd gear.
Also had some internal parts that are lighter such as a drilled sun shell, hollow output shaft, less clutches in the forward and direct drums, to name a few.
Non lockup 250s were in 4 cyl Vega"s, with a different bellhousing pattern.
Lockup 250's were in small cu inch stuff like 80s Malibu's, Regal's etc.
Not a trans I would use, when a 350 is identical in size and shape.

Bill

 

Actually it's a 200-4R, rather than a 200R4, not to be confused with a 700R4. Easier to find online if you have the digits in the correct order, good luck.

 

How much bigger is the 200-4R then a 350 as I can go that way if it's the same,30 years ago when I last seen a 250 I thought it was smaller but did notice it was light as I did not use the jack to put it back in the car.

 

The clutch in the 37 is not causing me any pain it's trying to move my legs in that small cab is what the issue is. It might be time to pass it to a younger and thinner member of the family and get me a truck with a larger cab.

 

The 200r4 and th350 are very similar in size.

 

200r4 would require the correct carb brackets for the trans cable because it upshifts that way....just go 350 turbo and save the hassle...350 downshifts with the cable and you can downshift manually ..

 

..... @milwscruffy , you did try......

 

A 200 is small in diameter and short. I believe the 200-4r is fairly long. No O/D in the 200 though.

 

https://www.jalopyjournal.com/forum/threads/2004r-vs-700r4.955180/