Olds64

I had a thought. Everyone always wants to convert their transmission to a 700R4 or a 200 4R. What about other overdrive transmissions?

I know Gear Vendors offers an overdrive/underdrive unit for most transmissions.

http://gearvendors.com/

I also know Allison makes overdrive automatic transmissions for school buses and military Hummers.

http://www.allisontransmission.com/index.jsp

Why doesn't anyone put an Allison transmission in their Olds? I'm sure it is stout enough to handle the torque of a BBO engine. Does anyone know of other overdrive transmissions that have been put into an Olds.

70 cutlass s

You can put any GM overdrive in an Olds. with help of an adapter. The reason people use 200r4 because you don't need computer to make it work and it bolts right up. With a 4L60E you need a computer. The stand alone computer cost around 1,000 plus cost of transmission. Gearvendors I have only heard good things about them, but they are not cheap plus you have to get a drive shaft made too. As far as Allison I'm interested to see what people have to say about that.

Olds64

Like you said an adapter would have to be made; however, you need an adapter for a 700R4. Just wondering if anybody had thought about this, or seen some oddball cars out there?

joe_padavano

If you're talking about the new Allison trans used in recent GM trucks, there are a few problems. First is the adapter plate. Second is the very large pricetag on even a used version. Third is the $1000 minimum for a computer controller. Fourth is that these things are huge and require significant floorpan mods to fit. Even the 4L80E requires floorpan mods.

distributorguy

I'm pretty sure the Allison also has a larger diameter, and you'll run into issues with transmission tunnel clearance.

joe_padavano

olds 307 and 403

People are also starting to use the new GM 6 SPD autos behind the 5.3's. Same problem, big and expensive. Those trans actually allow a truck to be used as a truck, no more worries towing like the 4L60-70E trans.

Olds64

I think when I originally posted this I was mostly curious. I did end up having my TH400 rebuilt (years ago) and it runs like a champ.

olds 307 and 403

Goly gee wilikers Batman, I am blind as a bat. I least he picked a thread made by someone still here.

distributorguy

Oops. At least I used the "search" function instead of asking the same info that's been addressed 300 times...