Transmission / Overdrive: 232 Clutch Options - Tremec 3550 swap

[Studebaker-Buick]

I recently picked up a TR-3550 (non-TKO), Ford configuration, with the intent on adapting it into my '54 Commander Coupe with the original 232/3spd-OD(T86E\R11). I've taken some trans bolt pattern measurements for both the T86 and the 3550 to come up with an adapter plate to machine (CAD screen-shots attached). There are a few details to work out for a custom machined pilot bushing and the spline location and its exposed length in relation to clutch motion but I also have some rudimentary questions regarding Studebaker bellhousings, flywheels, clutches, and release mechanisms. I'm having trouble finding these details with various searches though I have a feeling a lot of it is "common knowledge".

I believe it will be fairly straight forward to get this transmission into the original 232 bell with its clutch assembly and possibly even throw-out bearing/release linkage. I'm overlooking shifter placement and driveshaft length for now as I think these will be fairly straight forward tasks to solve once the transmission is in place. The adapter plate lays out pretty well and with a thickness of 0.55" seems to place the splines on the 3500 in the same region as the T86 would originally be. The images attached show the T-86 mounting face at the location that the bell housing face would be and the proposed adapter plate mates to that same face while the 3500 face is mated to the other side of the adapter plate. The T86 trans is the one shown transparent and has the longer pilot bushing diameter region. The adapter plate is also shown as transparent just to see more of how things are positioned. One main difference between the T86 and 3550 (besides the obvious) is the length of exposed spline. The T86 is about 2" of exposed spline while the 3550 is about 1.54", a difference of 0.46". Is this because the overall TO bearing travel of a lever style pressure plate is greater than a diaphragm spring style? I believe the GM 3550 bearing retainer is shorter (and possibly smaller OD on the TO bearing riding surface) so maybe I need to change to this bearing retainer to maintain the spline exposed length?

Here is a quick run-down of the dimensional differences between the T86 and TR-3550 (Ford config):
Item: T-86 / TR-3550
Bearing Retainer Bell Housing Pilot Diameter: 4.123" / 4.844"
Bearing Retainer TO Bearing Riding Surface Diameter: 1.497" / 1.431"
Splines: 1.125"x10 / 1.055"x10
Pilot Bushing Riding Diameter: 0.743" / 0.668"

Some base Studebaker questions I have are:
-Are all 232/259/289 Studebaker engine bell-housing bolt patterns the same? I think the answer is yes.
-Is a 259/289 10" to 10.5" clutch bell housing required to run a larger clutch on a 232 or is the 232 bell housing large enough?
-Is a 259/289 10" to 10.5" flywheel required to run these size clutches on a 232 or will it bolt to the original 232 flywheel? I imagine it won't bolt to it and the larger(or just different) flywheel is required.
-If the different flywheel is required, I believe the tooth count of the ring gear and possibly diameter are different meaning my original starter won't be compatible and will damage the starter and/or ring gear? I think I found this much on other posts.
-If needing a different bell housing, will it bolt right up to the 232 and the original bell housing located engine mount?
-It looks like the later 259/289 trans bolt patterns are different (wider and asymmetric) than the 232. Is that correct and do most not bother adapting modern transmissions to the older 232 style bells?

I'd like to migrate to a larger clutch and run the Jeep (75 CJ5 V8 application, AMS 01505) clutch for ease of sourcing and for cost. I would also like to entertain the use of a hydraulic throw-out bearing/slave cylinder setup. However, I think this would require moving to a diaphragm clutch since that's what most of the hydraulic slaves are meant to be used with.

Again, I think adapting to the original bell with a custom machined plate will work out (provided I answer the spline exposed length question) fairly well but would also like to plan ahead for a larger clutch and need to know the other items needed for that change.

Thanks,
Wayne

[Ross]

I'll admit to not understanding what advantages will accrue after all this work. The T86 gives you 5 ratios to play with, OK 6 if you really press it and imo is pretty well matched to the 232. Are you doing something remarkable to the engine that narrows the torque band?

If you make all these changes please document them so the next owner will be able to make repairs.

[Mrs K Corbin]

can you use the Ford Clutch disk? that may help with the splines, as the splines are just for the clutch disk anyway.

[Studebaker-Buick]

...please document them so the next owner will be able to make repairs.

Of course! I'll have to document things so that even I can make repairs!

[Alan]

Wayne, I hate typing, so my answers will be short. The 232 bell housing is too small. You need a 58 up bell housing with the Ford bolt pattern for the T86 and T85. You can use a Mcleod adapter plate that will bolt to the 58 up housing and the 3550 will bolt to the adapter plate. Only thing you have to do is machine down the front of the adapter plate for the Stude register size which is 4.680". While you are doing that you will have to narrow the plate (make it thinner). Since the adapter plate is .750" thick.

[StudeRich]

Ditto what Alan said, you started with the wrong Clutch Housing.

(1) It is too small for a decent sized Flywheel, 10.5 In. Pressure Plate and Clutch Disc.

(2) Yes the Bolt pattern is wrong on a '51-'54 Clutch Housing for a Ford pattern T-86.

[Studebaker-Buick]

Luckily I haven't started anything short of acquiring a 3550 and taking some measurements on that and a spare T86 I have so the car isn't even apart yet. Well that and research.
Thanks for the responses!

I will investigate this McLeod adapter.

[PackardV8]

Over on the Racing Studebaker forum, Alan recommends the truck bell housing. It saves a lot of work and adapters. I believe I have a spare, but they're heavy to ship. PM me if interested.

Yes, I'm sold on diaphragm pressure plates and hydraulic throwout bearings. The hot rod parts are wildly overpriced. Go with the OEM parts which match your transmission front bearing retainer sleeve. Use longer bolts and mount a second brake master cylinder beside your original to serve as a clutch master.

Ross said, "I'll admit to not understanding what advantages will accrue after all this work. The T86 gives you 5 ratios to play with, OK 6 if you really press it and imo is pretty well matched to the 232."

Yes, agree completely;, the T86 with a good floor shifter and manual kickdown button will give most of the performance of the 5-speed swap.

No, the T86 doesn't shift as well. No, the ratios aren't really usable as a 5-speed, as there's too little difference between 2nd-over and third direct, so it's really a wide ratio 4-speed. (FWIW, the truck T90 overdrive has wider ratios, so actually can be beneficially used as a 5-speed, but it's noisier and shifts even less well.)

Maybe define the goals. What is going to be achieved that provides $3500 in improvements/benefits? Then, if you're like me, you'll go ahead and do it anyway.

jack vines

[Studebaker-Buick]

...Then, if you're like me, you'll go ahead and do it anyway.

I'm glad I'm not the only one!

I do value the breadth of knowledge represented in this community so I agree it would be worth stating my intent (risking offending sensibilities) so at least I'll know if I'm making logical decisions and not repeating mistakes of others made over the decades.

I've flip flopped on intent for this car since I bought it but am more excited about the current plan(Might need to change my avatar name).
The plan is staying Stude powered but not retaining the original drivetrain for reasons of performance and ease of aquiring parts. While the engine doesn't fit all of these categories I am impressed with its construction (6 head bolts per cylinder, rod length to stroke ratio, etc) and I think it would be "cooler" to run the old iron in the car.

So the plan:
-Powertrain: Stude V8 powerplant, head work, cam, custom intake, exhaust/headers, EFI (Megasquirt-I've done these on other cars), and heavily turbocharged. Short block modifications is a discussion for another post. I picked up a pair of run of the mill 289 heads to modify. If I came across a 259 or 289 short block near by I would grab it but so far I haven't seen anything and thus the reason I'm still talking 232.
Drivetrain: TR-3550 trans, S-10/Blazer rear axle with disk brakes and 3.42 axle ratio, a clutch that makes sense, and a compatible driveshaft.
Brakes: 98-02 F-body front dual-piston and nearly 12" rotors(I'm mocking this up now on spare Stude running gear), rears are the ones on the blazer axle.
Wheels: aftermarket 17x7 front and 17x8 rear and tires that will fit (also discussion for another post).

Since my ultimate plan is a larger V8 and turbo then the bigger clutch will be needed. But I have a lathe and mill so for now I was entertaining mating the 3550 to the 232 bellhousing since I would essentially only be out the cost of the plate material (8"x12"x5/8" 6061-T6 aluminum is about $45, then then oil sintered bronze for the pilot). This is all assuming I can leave the stock clutch and stock release bearing and linkage. But, if there's s known path to utilize the larger bell and clutch now then I'll just do that.
What's got me hot to trot now is I picked up this 3550 on Craigslist for $500 and I'm riding that excitement momentum.

[PackardV8]

FWIW, the 232" is the strongest of all the Stude V8s. Add ported later heads, high boost turbocharging and we can already hear Dick Datson saying, "I told you so thirty years ago!"

jack vines

[Studebaker-Buick]

Honestly this would be my preference. At least on paper the advantage of the lower reciprocating mass means higher redline (provided valvetrain can keep up, and flywheel stays together) and I think I've read thicker cylinder walls due to the smaller bore. This comes with a caviot of valve size restriction. The bore diameter (3.375") is also very close to that of the turbocharged GM ecotech 4-cyl (86mm, 3.386"). Perhaps these factory inexpensive hypereutectic pistons could be fitting with an appropriate rod to make a good combination? I think the offset of the factory rod will be the main difficultly. Not to mention the 2" big end and 6.625" length...

[PackardV8]

Honestly this would be my preference. At least on paper the advantage of the lower reciprocating mass means higher redline (provided valvetrain can keep up, and flywheel stays together) and I think I've read thicker cylinder walls due to the smaller bore. This comes with a caviot of valve size restriction. The bore diameter (3.375") is also very close to that of the turbocharged GM ecotech 4-cyl (86mm, 3.386"). Perhaps these factory inexpensive hypereutectic pistons could be fitting with an appropriate rod to make a good combination? I think the offset of the factory rod will be the main difficultly. Not to mention the 2" big end and 6.875" length...

IIRC, the Studebaker V8 connecting rod length is 6.625”; still long, but not as much so. However, some have found the flathead Ford 7" rods from SCAT/Eagle better mate up with modern compression height pistons.

jack vines

[Studebaker-Buick]

Thanks for the tip. And I was remembering incorrectly. I'll change it to avoid anyone stumbling across false information.