No posts! Well, that's no good... How about a GM tranny ?

Hi all non-Ford guys,

I'm still trying to determine the best way to get an overdrive gear in a manual transmission for a GM application.

The T5 seems like the obvious choice since it is much cheaper than many of the alternatives (and I already have one). The problem is the bellhousing. The 3rd gen Camaro bellhousing would work (and have a hydraulic clutch too), but it tips the tranny over on a funny angle to increase ground clearance. This would be odd in my truck application since I need a shifter of some length. Does a standard bellhousing exist that will accept this tranny? It looked to me like the input indexing ring was an odd diameter that didn't match standard GM trannys.

The NV4500 looks like the best, but it's nowhere near cheap. Could bolt up though, with some floor pan modifications.

The GM 89mm 4 speed would be a good choice, but they don't appear to be very common anymore.

Then there's using an M20/M21/M22/T10 by changing the rear gears from 3.73 down to 2.73 or so. But I'd still like to have low speed grunt (it's a truck afterall).

How about the BWT56? Again pricey, and I'm not sure how well it would bolt up.

Then there's the Tremec 3500 used in S10s/1500s. Looks decent, but from what I've read, the parts for it are very expensive.

I've read an article about using a mopar A-833 too, but some minor input shaft mods are needed.

Anybody got any brain waves on how this might be best accomplished?

Thanks,
Greg

IIRC the 82-84 Camaro had a mechanical clutch and a T-5. It still turns the tranny over sideways, though.

Maybe a little metal work is in order. Remove the tailshaft housing, cut off the offending tilted mount, and weld on a straight one. Aluminum - what could be easier?

Heck, its easier than all that! I've got an '86 Camaro T5 bolted up to a late '50's truck bellhousing, hanging off the back of a '52 GMC 302. It bolts right up. Anything that you can bolt a Muncie or Saginaw to will take the leaning Camaro trans; you just gotta bend the shift lever to suit. If seat clearance is a problem, use the back end of a S-10 5 speed. See the Tech Tips on the Inliners web page for more info on that.

Hope this helps! Kinky6.

will the T-5 handle the 302 GMC?????

Yeah, IIRC, the NWC Camaro T5 for the 305" V8 was rated @ 295 ft/# of torque. The T5's for V6 & I4 models were not rated as high because they had lower gearing, esp. on 1st gear, and weren't designed to handle the torque of a V8 ( or a honkin' big 6 )!

Thanks for the ideas guys. The T5 I have is from my old S10. So it already installs straight-up and should put the shifter in a reasonable location.

Were input shaft mods needed to accomodate the pilot bearing? Seems to me the pilot shaft might be a bit long.

I'll probably try the tranny I have now and switch to a WC one later on (since I already have another project for the NWC T5).

One more project for the winter....

Greg

Hey, 292,

A couple of comments on your S-10 trans. If it was behind a 4.3L V6, it'll probably be o.k., but you woudn't want to go racing with it. I think that has a 3.5:1 1st gear. If it was behind a 2.8 or 4 cyl, you'll want to baby it. Those have 3.75 and 4.03:1 1st gears, and won't handle as much torque.

The input shaft on these is longer than it is on a Chevy 4 speed or the Camaro 5 speed. You'll need to cut around 1/2" or 5/8" off of the tip that fits into the pilot bearing. Then you will also need to grind a similar amount of material out of the center of the clutch disc, on the side facing the trans, so that it can slide further back onto the unsplined portion of the input shaft. Then you will also have to cut about the same amount off the end of the input shaft retainer ( the part the throw-out bearing rides on ).

If you have an old 3 or 4 speed laying around, you can match dimensions for the total length of the input shaft and the retainer. Also, check the outer diameter of the input bearing retainer. If it is not quite as large as the opening in the bellhousing, you could either swap retainers or have a spacer ring machined to take up the difference. This is not a problem with the Camaro trans.

There is a more detailed description of this at Inliners.com and at Stovebolt.com, under Tech Tips. Its nowhere near as complicated as it sounds. I hope yours is an older trans, with the cable drive for the speedo, cuz the electronic ones require a very pricey adapter for the cable.

Hope this helps, Kinky6.