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T5 Transmission

T5 Transmission
Allen9878

Allen9878

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Location
Central Wisconsin
Vehicle(s)
1980 Jeep Cj5 Renegade
I258 1987 Engine
Aisin Warner Ax15 Transmission
Dana 300 Transfer Case
Does anyone possibly have a T-5 Transmission they have lying around from their own change? I have a T-4 right now and am looking for a 5 speed. Thanks for the help.


-Bert
 
Allen9878 said:
Does anyone possibly have a T-5 Transmission they have lying around from their own change? I have a T-4 right now and am looking for a 5 speed. Thanks for the help.


-Bert
Click to expand...

I hear they're mostly used for "Trotline Weights".:laugh:
I'm sorry, good luck on you quest.;)
 
LongHorn said:
I hear they're mostly used for "Trotline Weights".:laugh:
I'm sorry, good luck on you quest.;)
Click to expand...

I say that because the T-4 & T-5 were notoriously weak transmissions.
Is there something wrong with your current Transmission or are you just looking for "Change"?
 
I need a five speed instead of my four speed. Was looking for the T-5 because I'm new to the game and don't wan't to have to much other stuff to change.
 
Allen9878 said:
I need a five speed instead of my four speed. Was looking for the T-5 because I'm new to the game and don't wan't to have to much other stuff to change.
Click to expand...

When you say you "need" a 5-speed.
Are you saying your rpm's are to high at cruising speed?
Your current Transmission is junk & you "need" another?:confused:
 
I will be doing some interstate driving and a five speed would handle it much better, the T-4 I have is in great shape but I would like to make the switch to a 5 speed.

-Bert
 
Allen9878 said:
I will be doing some interstate driving and a five speed would handle it much better, the T-4 I have is in great shape but I would like to make the switch to a 5 speed.

-Bert
Click to expand...

What size tires are you currently running?
 
Unfortunately I do not know my differential gear ratio. How do I figure it out? I am currently running 31 inch tires, and it isn't that its running poorly, it would just be easier on the truck to have the 5th Overdrive and run at a lower rpm.
 
Allen9878 said:
Unfortunately I do not know my differential gear ratio. How do I figure it out? I am currently running 31 inch tires, and it isn't that its running poorly, it would just be easier on the truck to have the 5th Overdrive and run at a lower rpm.
Click to expand...

What I am trying to say is, if your Jeep is stock & came with a T-4 it most likely came with a 2.73 gear ratio.
If I'm right it would probably not pull with a 30% reduction in gear ratio, so you spend money on a Transmission that is weaker than your stock unit & you get "0" benefit from the expenditure.;)

That being said you seem to think you can make this swap without changing any thing but the Transmission . If I'm not mistaken the T-5 is longer so you'd have to a least have new drive shafts front & rear.

To address you gear ratio issue, if your rear is stock & unmolested.
Your Model 20 differential should have a metal tag: D=2.73,B=3.31,A=3.54,GG=3.73,C=4.10.

If there is no tag (old vehicle) not surprising you can put it on jack stands shift in to neutral, make a chalk mark on the drive shaft & the tire. Then rotate the tire & count the revolutions of the drive shaft to determine your ratio.
 
Lets go back to what we've learned so far. The T-4 wich you have now is a weak Transmission . The T-5 that your looking to swap in is equally weak. You said its mainly a street Jeep with light offroading. Id say a T-4 or T-5 would be ok for that.

What you have to look at though is any T-5 you find is going to have somewhere around 100,000 mi. and up on it. You also dont really know how the previous owners treated it. Did they rock crawl with it and such ? And just how long till this notoriously weak Transmission breathes its last breath? Cjs of the T-5 era are 25 to 30 yrs old by now. While it will swap in with no difficulty what do you really gain? A 5th gear you'll very rarely use?

Lets find out that gear ratio and see where we're at. My Scrambler has 2.73s in it and Id never be able to use a 5th gear. Do you feel like your running out of gear in 4th or is this a gas mileage thing? If its the latter forget about it. You wont use it enough to see a significant difference.
 
Ford used a but load of T-5 's, call a wrecking yard ans see if the interchange manual can tell you anything about what would be the least likely to have been run into the ground. and what would be most likely to replace a T-4 with the least amount of work.
I think that you are mistaken about the efects of highway speed RPM's on an engine. the lower RPM's are not guarenteed to reduce wear, increase milage or extend the life of your machine. this is my own observation and I realy can't prove it one way or the other but I can say that a 5 or 6 hour run at 70 miles an hour always makes my jeeps run a whole lot better after a month or so of the 20 and 30 minute trips on the expressway, and low RPM stop and go stuff is a killer. You know, like off road driving?
 
Well that is why I'm asking, trying to glean some knowledge from you. What your saying makes sense and I will definitely have to think it over. In the mean time I will look to see what rear diff setup I have and that will most likely help me out also. I appreciate all of the input from everyone. Being new to the CJ world it really helps.

-Bert
 
I have a T-5 for sale out of my 85' that I am working on.
Also, have some widetrac axles with 3.31 gears in them, that will fix your
gear issue as well.
Let me know if your interested. Im just 1 state over from you in
Minnesota.
 
the T-4 & T-5 were notoriously weak transmissions, in France too, but I have never seen a broken T-5
All french CJ from 1982 to 1986 are équiped with. Ok with small french engine :o . But the mustang schelby (for example) is équiped with the same T-5 and it look ok with the lot of horse power.

So what :confused:
 
It was a T-5 but it was called the World Class T-5 . Its a much stronger version. The T-5 in your Jeep isnt near as strong as the World Class T-5 in Mustangs.
chevrier said:
But the mustang schelby (for example) is équiped with the same T-5 and it look ok with the lot of horse power.

So what :confused:
Click to expand...
 
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