Please help. 727 tail shaft will not go on.

[Bkl89]

I have a major issue assembling a 727. I cannot get the tail shaft on. The snap ring in the tail shaft housing will not line up with the groove on the output shaft bearing. it is about .070 away. I set the total end play to .030 with selective washers behind the front clutch. The only way to get it to line up is set the end play to .100. But then the issue will be the output shaft bearing will be taking a thrust load which it's not designed to do. I thought about leaving the endplay at .030 and stacking .070 worth of tail shaft to case gaskets or just leaving the snap ring off. It sits in a machined pocket and the snap ring just keeps it from rotating. I have looked everywhere and never heard of this type of issue. Any suggestions? Thanks

 

[Greg Ducato]

I would install the extension housing without loading the front of the trans beyond the input planetary. Check for exessive endplay in the rear gear train once the housing is bolted on.(it is usually fine) You can shim a rear annulus washer if needed or use a selective snap ring on the input shaft to get that dialed in to where you like it. Then load up the front and check end play at the input shaft, I usually find a #1 or 2 between the drums and a #3 on the stator gets me where I want to be. You arent checking endplay for the whole unit, you are checking it seperately for the front and rear and they are independent of one another. You have to have the rear of the trans buttoned up first before you can set the front. Hope that makes sense.

 

[dvw]

I have a major issue assembling a 727. I cannot get the tail shaft on. The snap ring in the tail shaft housing will not line up with the groove on the output shaft bearing. it is about .070 away. I set the total end play to .030 with selective washers behind the front clutch. The only way to get it to line up is set the end play to .100. But then the issue will be the output shaft bearing will be taking a thrust load which it's not designed to do. I thought about leaving the endplay at .030 and stacking .070 worth of tail shaft to case gaskets or just leaving the snap ring off. It sits in a machined pocket and the snap ring just keeps it from rotating. I have looked everywhere and never heard of this type of issue. Any suggestions? Thanks

You don't have the output shaft bearing on backwards do you? Groove faces the front.
Doug

 

[PDFROGMAN]

stand the unit up on the bench , spread the snap ring over the bearing bolt the extension housing to the case, take a screw driver lift the bearing up the snap ring should snap in

 

[SwedCharger67]

While checking the input shaft endplay, you should push the output shaft forward to remove any slack there, assuming you have the snap ring etc. in place.

 

[Bkl89]

I would install the extension housing without loading the front of the trans beyond the input planetary. Check for exessive endplay in the rear gear train once the housing is bolted on.(it is usually fine) You can shim a rear annulus washer if needed or use a selective snap ring on the input shaft to get that dialed in to where you like it. Then load up the front and check end play at the input shaft, I usually find a #1 or 2 between the drums and a #3 on the stator gets me where I want to be. You arent checking endplay for the whole unit, you are checking it seperately for the front and rear and they are independent of one another. You have to have the rear of the trans buttoned up first before you can set the front. Hope that makes sense.

Thank you for the excellent and helpful reply! I followed your instruction and installed the extension housing first and then set the gear train end play then set the front. It is perfect now. That rear snap ring completely changed everything. Thanks again I would be lost if it wasn't for the helpful members here.

 

[coloradodave]

Good call, Greg. This was one of the most helpful group of posts I've read. Great information and advice from all.