RAT transmission install help

[Bucky71]

Hey Everybody,

I’ve rebuilt and assembled the RAT transmission, the adaptor, and the Dana 20 - they all came out great and I’m in the process of installing the assembly today.

I’m using a hydraulic lift cart and ratchet straps to get everything aligned with the help of a friend, but getting hung up - the transmission face is an inch from the bellhousing. The smooth input shaft sleeve is into the throwout bearing, and the clutch release lever moves freely, so it’s not binding on that.

The angle and alignment look perfect, and we have wiggled and shifted the assembly every way I know how.

I know the pilot bearing is a small target, but the shaft is tapered - I’m surprised we didn’t stab it pretty quickly.

I have rotated the motor a tiny amount to try to line up the clutch friction plate splines with the input shaft about a half dozen times, in case that was not meshing.

Any ideas? I do have the tool installed to lock the RAT into gear - should I take it out and get the transmission into neutral?

And does anyone have a picture or diagram of what the shift levers look like when it’s in neutral?

Thank you! Hope y’all are having a nice Saturday!

 

[B RON CO]

Hi, you didn't mention using a clutch alignment tool to line up the clutch splines with the pilot bushing. If you are 1" from the bell housing, the input shaft is through the clutch splines. Some guys cut the heads off off extra bolts and install them into the bell housing to guide the tranny in place. Personally, I attach the bell housing to the tranny and slide the bell housing to the block. Good luck

 

[DirtDonk]

With the transmission in place still, find a way to release the clutch using the clutch lever. An extra person, some leverage against it, long prybar, or your foot and leg power.
A inch sounds like a little too much to be just the pilot bearing, but that’s still the most likely culprit.
Even with a decent alignment tool, a fraction of an inch off is all that’s needed to jam up the assembly.
Release the clutch and the disc will shift with the transmission and everything will slide forward. If it doesn’t, you’re hooked up on something else.
The long bolt trick is great, but don’t use them to pull the transmission forward against the force.
Simply use them as an alignment aid.

 

[.94 OR]

The headless bolt trick works great.
Cut notches in the exposed ends so you can "flat bit" them back out when done.
By having these in place, you can sort of lever the transmission around modifying the snout end of the input shaft as you have someone release a little pressure on the pressure plate.
Good luck.

 

[Bucky71]

Great tips guys - I’ll try these today. Thank you!!

 

[DirtDonk]

With the bell housing in place, you can actually fully connect the mechanical linkage for the clutch.
To the point where nobody has to really stress over moving the clutch fork by hand. Someone can just get inside the vehicle (carefully since someone else is underneath!) and depress the clutch pedal.
It takes surprisingly little movement, to loosen the disc enough to let it move.

 

[SLOWnEASY]

Had this problem the last transmission I put in. Turned out the cheap plastic clutch alignment tool did not get the friction disc anywhere near centered. I finally pulled the transmission back down and stuck my head up into the tunnel behind the clutch and could see the misalignment by sight. Loosened the pressure plate bolts and used my fingers to center the disc then then slowly tightened the pressure plate back up. After that the the transmission slid right in.

 

[DirtDonk]

Yep. Cheap plastic, or cheap wood (yes, wood in the old days) tools are haphazard at best. Seems like it's worse trying to eyeball it with the tool, than without one just like you did. More success without the tool.
Never had a problem with my first car's clutches, because the "alignment tool" of choice was an actual transmission input shaft! Very accurate and hard to get wrong.

In the last 40 years though, the "release the clutch slightly" trick has never failed me yet. As long as the disc is close, it always pops right in when loosened up. Just like you did by loosening the cover bolts, but takes less time and you don't have to drop the trans yet again.

Paul

 

[Bucky71]

Guys I finally got it!!

It was a combination of all of the things people have mentioned. The thing that was really a game changer was an inexpensive bore scope - being able to see the alignment of the splines on the input shaft and the friction disc was super helpful.

The other key thing was making the 4” alignment dowels out of bolts that are mostly shank, and then cutting a flathead slot in each one for removal. Killer suggestion.

Thanks to all of you for your excellent advice and support! Should be driving by next weekend