Topic: 7M-GTE Swap Tranny Question

[wrenchtech]

I did a search and it seemed like this question was answered a couple of years ago, but, I just want to double check.

I want to do a Supra 7M-GTE, turbocharged,  I-6 cyl,  engine swap into a first generation 4runner and I would like to run an R series transmission,  preferably an R-151F. I understand that the 7M-GTE Supra bellhousing will bolt right up to the R-151-F, but, that the input shaft on the R-151-F is too short. I've heard that an input shaft from a mid to late 80's R-154 Supra 5 speed will swap into the R-151 to make this work. Is that right?

Another idea just occured to me. How much is the difference in length between the R-151 and the R-154 input shafts?  If it's 0.75" ( three quarters of an inch),  would a fabricated extension adapter attached to the end of the R-151 input shaft or an extra tall pilot bearing adapter thingie do the trick? Would there still be enough spline in contact with the clutch disk hub?  If any one can figure this out it's got to be Marlin's Toyota driveline guru's.

I'm also reminded to ask if Marlin ever made any transmission rebuilding videos to go along with tranny rebuild kits?

Matt

[Cracker]

IIRC, the R151 input is 30mm shorter than the R154.

One of these days (once the temps get back into the 30°s), I could measure them both to make sure....

I would be REALLY interested in hearing if the inputs are swappable without changing the gearing. I really doubt it is possible at all, but I sure would like to hear about it, since the only thing holding me up from swapping a 7MGTE into my 80 mini is a way to mate it with my R151....

I'm having a really hard time finding anyone capable or willing to cast a custom bellhousing to mate the two...

[wrenchtech [OP]]

Marlin and I were talking on the phone a couple of years ago about the differences between the Jeep AX-15 (a close relative of the R series), the R-151, the R-150, the Supra R-154 and the late model R-150 tranny in the Tacoma.  Our unscientific survey came up with the following input shaft "stick-out" lengths:

Toyota R-154 = 7.25"  (Toyota Supra Turbo)
Toyota R-151-F = 6.25" (1986 -1987 4cyl turbo 4wd, gear transfer case)
Toyota R-150-F = 6.25" (1988 -1995 V-6cyl, 4wd, chain transfer case)
Toyota R-150-F = 7.5"  (1996 -2002 V-6 Tacoma, 4wd, chain transfer case)
Jeep AX-15  =  7.5"  (1989 -1999 6 cyl, 4wd)

At the time I had a Buick aluminum V8 motor that I thought I wanted to put into an '84 toyota 4x4 pickup. Novak Conversions makes a bellhousing adapter to mount an AX-15 to a GM bellhousing. The Ax-15 and the Toyota R series have the same mounting face so the only thing preventing the Buick/R151 swap was the fact that the R151 - R150 input shaft is too short for the AX-15 bellhousing.  Marlin suggested that a 1996 or later R-150 input shaft could be installed in my R151. It seems like an R-154 (Supra) or a late R150 (Tacoma) input shaft should swap into the R151 and early R150 trannys, but, I've never talked to anyone who has actually done it, so, I thought I'd ask the experts.

[Marlin]

Matt, the R154 gear set has a higher first gear which uses a difference input and front countershaft gear ratio. So only 3.83 first gear (3.0 V6) and 4.31 first gear (22R turbo) can be interchanged.
I tried to do a trans video, it was a disaster.

wrenchtect, the gear helix angle on the longer input and countershaft of the 96' and newer R150 is greater and will not interchange with the earlier shorter input gearsets

[wrenchtech [OP]]

wrenchtech, the gear helix angle on the longer input and countershaft of the 96' and newer R150 is greater and will not interchange with the earlier shorter input gearsets

Marlin,

How about a Taco tranny behind the Supra bellhousing with a Marlin Crawler t-case adapter ?  Input shaft length is about the same, spline is the same as the R154; right?

Matt  

[dubmatic]

I know this is an old post but did you ever figure out the answer? would the taco transmission with the turbo supra bell housing work?

[4mogger]

I have little to contribute to this thread on a technical basis, but I REALLY want to know the answer to this question as well.

One other thought.... You may be able to space the flywheel out to compensate for the shorter shaft on the other trannies. That would depend if the clutch fork pivot and all that stuff is a inch back as well as the shaft... I don't think this would weaken the system much. If you used a solid spacer (like a mini wheel spacer), you would not introduce bending moment stress into the flywheel hardware. IT will still theoretically be in pure shear (just with two shear areas, same stress as before the spacer though).

[4mogger]

Ok I was thinking about what i said up there ^ and it is purely retarded.

IF you had a 7M bell housing and you moved the flywheel out, the clutch pivot and fork hole would both be off by exactly how much you moved the flywheel wince they are BOTH part of the SAME FRIGGEN HOUSING.

[4mogger]

I'm your huckleberry.

http://www.supracharged.com/4runner/7mswap.shtml

totally redneck... dunno how well it would hold up, but someone "customized" the two bellhousings

[gravityfrog]

If anyone is still interested, I read over on supracharged that the output shafts exchange.  You would be stuck with the higher gearing from the R154 but you could then bolt a T-case to the back.