Good tranny replacement for 82 CJ7 258

Sully · #1 (**permalink**) 11-24-2005, 09:12 PM

Well my tcase is fine but my tranny has taken a dump on me. Mainshaft destroyed and my bearings are toast. It was a T-5. I was just wondering what your thoughts were on a replacement tranny. I was thinking somewhere along the lines of a T-18. It has to be a manual tranny and a good match to my 258. Any ideas?

TwistedCopper · #2 (**permalink**) 11-25-2005, 09:51 AM

If you can find a T-18A from a 77-79 it will have the granny low

Sully · #3 (**permalink**) 11-25-2005, 11:37 AM

That's why I want the T-18 for the granny low. Will it bolt right up to my jeep?

Junkpile · #4 (**permalink**) 11-25-2005, 01:54 PM

You'll need an adapter for the Tcase. Make sure you get one that you KNOW came out of a CJ, or you might end up with input shaft nightmares.

Whether or not it's a good match with the 258 is up to you. For me, it's a crappy conbination. For you, where you do alot of high traction slow speed rockcrawling, it would probably be much better. It also depends on the 258. A factory 258 is great right off idle to about 3500rpm. You'll want to stretch it out a little further than that with the deep first.

Have you considered upgrading your T-5? Sure, it's kind of a turd, but the gearing is nice and you've been rowing that thing for a long time now haven't you? Maybe one of those World Class T5s?

TwistedCopper · #5 (**permalink**) 11-25-2005, 01:56 PM

Quote:

Originally Posted by Sully

That's why I want the T-18 for the granny low. Will it bolt right up to my jeep?

That's what I figured, but I thought it should be mentioned the 77-79 T18A are the ones with the imfamous granny gear.

I believe the "A" version had a slightly different bolt pattern than a regular T18, something about the two bottom bolts...

I have links with more info in my other computer but that's an hour away. I'm sure Junkpile could tell ya. Sorry that's all I got.

Sully · #6 (**permalink**) 11-25-2005, 02:45 PM

Should I be worried about losing my overdrive? I will be running 4.88 and 35's. What kind of top speed am I looking at?

Junkpile · #7 (**permalink**) 11-26-2005, 02:23 AM

I can't remember the year thing. I want to say that only 79 got the granny first model......or maybe 79 was the one that got the close ratio.....I don't know. Just make sure you get a T18a from a CJ.

Sully, I'm just guessing here, but it seems like you go on alot of long distance wheeling trips in your Jeep, so overdrive would be a nice thing to have. I feel funny about even getting close to recommending a T5, but I think a granny geared transmission is a choice that should be heavily weighed before jumping on it. It's the best thing since sliced bread to some people. Do you know anyone that has one that will let you spend some time behind the wheel? I mean, if rockcrawling is your thing and you can live without the overdrive, then it might be for you. You can always play with the gearing in other areas to compensate. With the granny 1st and loss of overdrive, you might be better off swapping to more highway friendly diff gearing and then gearing down the tcase for offroad.

Sully · #8 (**permalink**) 11-26-2005, 02:05 PM

I think I am going to rebuild my T5. My gears are pretty low as is I was just being greedy. heh Thanks for the help.

TwistedCopper · #9 (**permalink**) 11-26-2005, 06:32 PM

Quote:

Originally Posted by Junkpile

I can't remember the year thing. I want to say that only 79 got the granny first model......or maybe 79 was the one that got the close ratio.....I don't know. Just make sure you get a T18a from a CJ.

77-79... That much I'm sure of.