transmission planning for a CJ7

As far as I am aware, you now have the best combination going, the Borg Warner 'World Class' T5 with the Dana 300 t-case. That T5 is the same one Ford puts behind Mustang V8's and is a strong one.

I have abused mine, run it totally dry 20 miles from a road and came limping out with it going bang! bang! bang! in every gear except 3rd, only to fill it up and keep on going. That was 6 years ago too....

I kinda like mine.

Mike

Rusted wrote:

Is the T-5 not concidered to be a "light weight" transmission?

I have felt like I have abused mine as well. With the high miles I know it needs a rebuild. So if price was similar between rebuilding my T5 and a T18a would you would still prefer the T5? How come offroad.com calles the T5 a "light weight" tranny, and the T18 a "heavy duty". A V8 Mustang is still a 2500 pound ish car, where the T-18 was used in 3/4 and 1 ton trucks. Thanks for your input.

If it was the same cost, then I might go for the heavier one seeing as I don't use the T5's overdrive anyway.

But then there is 'heavy' and 'heavy duty' too to consider. That T18 has a cast iron case and the T5 has an aluminum case. Does this make the T just 'lighter' or 'lighter duty'?

Mike (with a super light 'glass Jeep)

Rusted wrote:

Hi Mike. I always thought that the 80s Jeep CJ T5s were of the non-world class variety. Please tell me I am wrong and that my 86 is a world class T5 :)

You are wrong sort of... I forgot about that, they didn't start with the world class ones until 85.

Mike

I read that they started with the World Class ones in 85, so likely yours is the regular. Ours could be too, but I have seen a few places that say otherwise. Here is one:

Rusted wrote:

Oh yes, they also changed the tranny fluid in the 1985 and 86 owners manuals to state to use gear oil. The older T5's called for ATF.

Mike

Mike Roma>

So do you still have a strong argument for me to keep my '83 T-5 that is non World Class? I do like the 1:.76 5th gear because it gives me a wider range of gears. I will lose that if I change transmissions.

You get them in TVRs ? Didn't know that. Wish I could afford that T440R - a

The only difference is the world class one is supposed to be smoother shifting.... Same guts otherwise I believe.

My overdrive is useless with my 3.31 gears and 33's. It will still pull along, but it lugs the engine so the gas mileage goes to crap. I stay in 4th on the highway and get about 23 US mpg.

I don't know what the real advantage for changing unless it was cost. I have never heard of anyone breaking the 'light' aluminum T5 case so don't see what a cast case will add besides weight.

As Bill noted, the lower 1st is a thinner gear, but I very seldom use

Mike

Rusted wrote:

not even close - the 5.0 litre there makes 330hp or 66hp/litre compared with the TVRs 105hp/litre.

Dave Milne, Scotland '91 Grand Wagoneer, '99 TJ

Yes it's very light weight. But it depends on what you are gonna be doing with it. it will last forever behind a 258 with small tires. I put my t5 from my 85 cj7 behind a built 304 with 4.56 gears and 36x12.5" tires and it lasted about two weeks. It worked fine on the street and as soon as I hit the mountains it exploded. I would upgrade - no CJ t5 is world class, AMC was too cheap for that.

Another option for you would be a T176 that would bolt right up to your 258 and d300 and you could even use the same bell housing/clutch. The bell housing would need some minor machine work (new holes drilled). The t176 is a medium duty and was put behind v8s from the factory. It has been in mine for 4 months and i have seen some pretty good trails with it.