Scratching my head....

Jeepasaurusrex · Aug 16, 2012

I recently built an AMC 304 for my CJ7. I ran the motor on a test stand to break it in etc, so I know its good. My tranny is a T-18 that I have had in the Jeep before, but just had it rebuilt. It was behind my inline 6 prior to this. The T-case is a Dana 300 that is clocked flat.

The motor was set into the frame first. Then the transmission/T-case were lifted into place and bolted up. The clutch is a stock pressure plate and the clutch disc is from a 94 Mustang Cobra 5.0 (to match the input shaft on the trans in spline/outer diameter.)

Tonight, I finally got my hydraulic clutch all assembled and installed. I bled the system so I got a good firm pedal. It was at that moment I tried to shift gears in the transmission. It wont go into any gear. With the T-case in gear, I cannot move any of the outputs. I hooked up the starter and tried to bump over the motor with no luck. The whole rotating assembly is locked up.

I am trying to figure out where to start. I am thinking maybe the pilot bushing is not deep enough and the input shaft is crammed into it. But, when I bolted the transmission in, the input shaft slid right in and everything bolted up just fine. I did not have to use the bolts to draw the two together.

I am really stumped here...:wtf:

WA-Wheeler · Aug 16, 2012

It wont even dry shift??

WHITE TRASH1 · Aug 16, 2012

Had an issue like that in a friends '7 with a t18/20 combo. Fixed it by supporting the trans and taking the t case off and bolting it back on top to bottom with a jack under the t case. Even though the bearing retainer on the t case indexed nicely into the trans it was juuuuuust enough play to bind the whole setup.

WA-Wheeler · Aug 17, 2012

WHITE TRASH said:
Had an issue like that in a friends '7 with a t18/20 combo. Fixed it by supporting the trans and taking the t case off and bolting it back on top to bottom with a jack under the t case. Even though the bearing retainer on the t case indexed nicely into the trans it was juuuuuust enough play to bind the whole setup.

Really? that's crazy, never seen that happen before but kind of makes sense....

whatthe? · Aug 17, 2012

Somebody might have a better suggestion but I'd start by removing the t-case and seeing if everything moves, if not, move forward and find out where the bind is.

WHITE TRASH1 · Aug 17, 2012

WA-Wheeler said:
Really? that's crazy, never seen that happen before but kind of makes sense....

Yea it was messed up, the t case wouldn't shift into low bolted up tight but once it was loose and you banged on the shifter it'd go in. Tighten it back down and when coming out of low it'd BANG as the shift collar came off the misaligned input shaft. If I lifted the case up while it was loose it would slide right into gear. I had that fawking case out 4 damned times figuring it our. I stick to toyota's for a reason... :haha:

crash2 · Aug 17, 2012

WHITE TRASH said:
Had an issue like that in a friends '7 with a t18/20 combo. Fixed it by supporting the trans and taking the t case off and bolting it back on top to bottom with a jack under the t case. Even though the bearing retainer on the t case indexed nicely into the trans it was juuuuuust enough play to bind the whole setup.

That makes no sense. If that was the case then under load/torque that would constantly happen. Thats why just about every adapter has some sort of overlap from one unit to the other to keep them aligned and I can't think of one that isn't...

WA-Wheeler · Aug 17, 2012

WHITE TRASH said:
Yea it was messed up, the t case wouldn't shift into low bolted up tight but once it was loose and you banged on the shifter it'd go in. Tighten it back down and when coming out of low it'd BANG as the shift collar came off the misaligned input shaft. If I lifted the case up while it was loose it would slide right into gear. I had that fawking case out 4 damned times figuring it our. I stick to toyota's for a reason... :haha:

I thought those little 20's were light... :redneck:

Jeepasaurusrex · Aug 17, 2012

The T-case and Tranny were bolted together prior to putting into the Jeep. They both moved free and shifted fine. It was only after I joined them to the motor that they bound up. :corn:

crash2 · Aug 17, 2012

Jeepasaurusrex said:
The T-case and Tranny were bolted together prior to putting into the Jeep. They both moved free and shifted fine. It was only after I joined them to the motor that they bound up. :corn:

The only time I have ran across this is when an input shaft was too long and caused too much preloading against the t-case...

WHITE TRASH1 · Aug 17, 2012

crash said:
That makes no sense. If that was the case then under load/torque that would constantly happen. Thats why just about every adapter has some sort of overlap from one unit to the other to keep them aligned and I can't think of one that isn't...

Whether it makes sense or not it is what happened regardless. I measured the trans case and the bearing retainer in the t case and it had roughly .04" clearance if I remember right. It was enough to hold the bull gear in the 20 out of alignment. Lifting the t case with a jack and cranking down the top bolt first then working down did the trick. He has been wheeling the rig for over a year since we put it together last.

Jeepasaurusrex · Aug 17, 2012

Well, since the Dana 300 input is splined, that does not apply.

I am going to loosen the bolts holding the transmission to the bell housing and see if that frees it up.

Jeepasaurusrex · Aug 20, 2012

Got it figured out! I spoke with my friend Dan who rebuilds transmissions for a living. He sat down and was in deep though for a minute and suddenly says "its in both a forward gear and reverse at the same time"

He was right. The shift forks were not where they should of been. I had it fixed in under 2 minutes. Once I got the shift forks where they should of been, I dropped the shifter back in and wala! It works! Everything is free now.

I can't tell you how relieved I am that I don't have to pull the tranny again.

:cheer::cheer::cheer: