a1 trans/tc

[zeke57]

Before I start to reassemble the drivetrain and while it is accessible what should I do with the trans and t/c. I bought both of them already removed from the vehicle so I do not know their condition. Not really looking to do a rebuild unless necessary just wondering if there is a common problem with these that I should address before reinstalling.

[wesk]

Unless you have a fully equipped shop with lifts and hoists then if you have to crawl under that jeep and pull that tranny & transfer out for needed maintenance it will probably take you 1 hour to determine you should have checked their internal condition before you installed them!

A thorough visual inspection which will require partial disassembly of each will reveal any obvious issues. If your own lacks the training/skill to understand what you see while they are open invest in the help of a buddy who has this type experience to help you.

Some common issues:

1-Corroded internal gears and /or bearings. (This means take them all the way apart for a detailed inspection.)

2-Damaged gear teeth. (This means replace any damaged gear which will require further disassembly)

3-Loose shafts. (again this dictates further disassembly.)

4 - Bad bearings. (Again each bad bearing must be replaced.)

5-Shifter fork wear or worn shifter poppit balls. (Again dictate further disassembly

6 - Worn synchronizer brass gears and sleeves. (Again further disassembly)

If you have no experience with the T90 and D18 you may still find those units performing poorly after the thorough inspection if you did not take her all the way apart.

There is also a very small bushing in the middle of the flywheel that support the T-90's input shaft when it's installed. Definately check the fit of that bushing to your tranny's input shaft

[zeke57]

I have zero experience with this or any transmission but I am eager to learn. Wes could you tell me where to start to evaluate my tranny/tc. Thank you.

[wesk]

Start by reading thru the manuals for them and reviewing the overhaul guides for them. This will get you intimately familiar with them. Then clean their exteriors up the best you can. Then pull their covers off and start inspecting them visually. If you spot anything that concerns you and you can't resolve what it is or how to proceed take a detailed photo or two and post them here and ask.

The manuals you want to revue are:
TM's 9-8012, 9-1804B. civvy service manual SM-1002

The overhaul guides are at:
http://www.willystech.com/wt/T90Rebuild ... ebuild.htm
http://www.willystech.com/wt/Model18TCa ... rCase.html

You make yourself familiar with these pubs & guides and you'll become a proficient Spicer T90 & D18 maintainer.

Now there is a trick to getting the answers you want when you post a question here.

1 -ID the jeep and part we are having an issue with.

2 - Clarify that the jeep and the item are both stock or they are modified in any way.

2 - Describe the issue

3 - Use photos. They truly are worth a thousand words.


You can insure we always know what model jeep you are asking about by simply going to your profile and adding a signature block. In this signature do what most of us do. List your vehicles by make, model, year.

Also in this signature block post your real first name. These cute CB type handles we come up with for our usernames are just that, cute. The majority of the folks who can answer your questions and help you out prefer to get on a regular, old fashion first name basis with you. They also like to know where you are located so if your close by they often will volunteer to come by and give you a hand. So add your location at least State but City also helps.

[zeke57]

I popped the top cover off the t90 and to me everything looked good but I am no expert so I called a person who say's that he has rebuilt at least ten of the t90's and he told me what to look for. He said to pay particular attention to the second gear and again he explained to me what to look for but all looked good. The only gear that has some wear is the reverse/1st.gear but I read where that is acceptable. Other than that I did not see any broken or chipped teeth and the tranny seems to be pretty clean and un-abused. Thoughts anyone.

[4x4M38]

If you have them out of the jeep now is the time to do anything.

Once they are installed and you find something wrong it’s too late
and you’ll be yanking the whole mess out to fix it.

Take a little time and go read those two rebuild guides. They were
written for guys just like you and me, and have comments by others
who have used them.

What does the oil look like? Are there any shiny flakes that
make the oil look like metal flake paint? Is it gray?

Again, go read those guides.

Then decide if even a partial teardown to get a thorough
examination is worth it, or if you want to roll the dice.

Just my two cents.

[pajeff02]

Our jeep was running good and the transmission was shifting great, until our last ride. After coming up our hill I went to pull it into third and the shifter would not move. Fortunately, this happened close to home and we were able to make it the entire way in second gear. Upon removal of the shifter assembly, I found that two of the three keys on the synchronizers were up out of place and were blocking the clutch gear from sliding over into third. About to tackle a full rebuild to remedy this.

There is a good video of this issue on YouTube - I think I searched "T-90 stuck in 2nd". Apparently, the keys are stamped steel and the lips on the end wear away allowing the key to slide out of place.

[Xamon]

Just my one cent but if you are not doing a full disassembly then stick a magnet down into the bottom and see what you fish up. A few tiny particles is normal wear but anything else and you could have real problems. If uncertain then again as Wes said pictures are your friend.