86 CJ7 - 4Cylinder - T5 Transmission Problems

ewotp

New member
City
Fort Worth
State
TX
#1
Hey there I am new, I bought an 85 CJ7 with a 4 cylinder 5 speed manual T5 transmission that needs to be rebuilt. Should I replace it with a better transmission, like a T176? I have the Dana 300 so is there an adapter plate necessary for this type of conversion.

Any suggestions? Thanks!
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barrys

Scrambler Junkie
LIFETIME
CJ-8.com Member
City
East Norriton
State
PA
#2
That's a personal call. T5 has overdrive and is already there. T176 is stronger, no overdrive, would require driveshaft changes(95% sure anyway).
 

walkerhoundvm

Just trying to stay upright
LIFETIME
CJ-8.com Member
City
Cave Creek
State
AZ
#3
From the looks of your setup, I'd say probably. The lift and bigger tires would benefit from a stronger transmission like a T176.

Do you know what your axle gearing is? How fast do you typically drive? You can use a site like grimjeeper to determine engine speeds for your tire, gear, and transmission setup and see if you're OK with a 4spd or if you need an overdrive 5spd, and at the same time make sure your gearing is appropriate for your tire size. For all we know you're running 35s with a 2.73 gearing and no tranny would be able to keep up with that.

You will need new driveshafts with the T176, which'll run another $300 or so + ujoints and straps. You'll have to look out for a T176 that comes with an adapter to the D300, too. Some people try to sell them without the adapter and then you have to hunt for it. While the T176 is shorter than the T5 by a few inches, you'll still have to see if you'll need a double cardan setup by measuring your incline angle from your rear diff to your rear output shaft on your transfer case.

Before you dive too far in, you might just consider a near-complete drivetrain swap to get rid of that 4cyl...maybe a YJ 4.0 with fuel injection and a AX15 behind it mated to the D300. No matter what, give this a lot of thought so you aren't wasting time and money on a short-term fix.
 

ewotp

New member
City
Fort Worth
State
TX
#4
From the looks of your setup, I'd say probably. The lift and bigger tires would benefit from a stronger transmission like a T176.

Do you know what your axle gearing is? How fast do you typically drive? You can use a site like grimjeeper to determine engine speeds for your tire, gear, and transmission setup and see if you're OK with a 4spd or if you need an overdrive 5spd, and at the same time make sure your gearing is appropriate for your tire size. For all we know you're running 35s with a 2.73 gearing and no tranny would be able to keep up with that.

You will need new driveshafts with the T176, which'll run another $300 or so + ujoints and straps. You'll have to look out for a T176 that comes with an adapter to the D300, too. Some people try to sell them without the adapter and then you have to hunt for it. While the T176 is shorter than the T5 by a few inches, you'll still have to see if you'll need a double cardan setup by measuring your incline angle from your rear diff to your rear output shaft on your transfer case.

Before you dive too far in, you might just consider a near-complete drivetrain swap to get rid of that 4cyl...maybe a YJ 4.0 with fuel injection and a AX15 behind it mated to the D300. No matter what, give this a lot of thought so you aren't wasting time and money on a short-term fix.
Great info - if I decided to do an engine swap - do you think the YJ 4.0 is better than going with the Chevy small block? Do you know know if the AX15 is mated with the Dana 300 without too much conversion - thanks again!
 

walkerhoundvm

Just trying to stay upright
LIFETIME
CJ-8.com Member
City
Cave Creek
State
AZ
#6
Yep - that's the adapter you need.

For mating the AX15 to a D300, you'd just need a clocking ring - usually about $100. Many places carry them, some are better quality than others.

You're getting into a whole new bag of worms with an engine swap no matter what, but at least with the 4.0/AX15 you might be able to get them both together for not too much money. For the Chevy swap, from experience, it's going to run you probably double - but the thrill is easily double as well, and probably quadruples what you have in there now.

There are a lot of members here who've done all sorts of drivetrain swaps. Some of the more common are the 4.0/AX15 and the 5.3LS/4L60e(auto) for example, with every variation in between. I swapped a 5.3/AX15 and it probably ran me close to $5-6000 all said and done. I"m not sure if I'd do it again, but it's a lot of fun compared to the 6cyl I had previously.

Best to sit down and give it some thought like I said. I don't even want to remotely convince you of a complete drivetrain swap, you have to first decide what you want and how much you want to spend. With an engine/tranny swap you'll have to plan for driveshaft changes, installation, adapters, engine mounts, wiring harness, and maybe even gearing changes. The T176 swap starts to look comparably simple and cheap.
 

Belizeit

CJ-8 Member
CJ-8.com Member
City
River Ridge
State
La
#7
ewotp not trying to hijack this but it is expensive. I took out a 4 cyl. w/T4 and going back with a I6 258 and T176. All upgraded and Holley Sniper and new MSD distributor and transfer case upgraded to 4:1 gears and steering parts. I know I'm probably at a cost of more than what I bought my Jeep new 36 years ago. I thought about this for many years before starting. Mainly V8 or not and decided I just didn't want to go in that direction. I just don't have that need for speed.
 
City
East Wilton
State
ME
#8
For under a grand you can find a 90's wrangler complete and running. That is the best way that I know of for a 4.0/AX swap. Depending on the year and how good you are at the wiring stuff, You can go OBD1: pretty easy or OBD2: Little more involved...either way having a complete rig to use is the way to go in my opinion.
 

ag4ever

Average Nut
LIFETIME
CJ-8.com Member
City
Richmond
State
TX
#9
Might be able to find a YJ in the rust belt for around a grand, but in Texas you won’t touch a running Jeep for less than 3 grand (excepting a rare deal).

In Texas the drivetrain wears out before the frame and body rust out. Unless it was a beach buggy.
 
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