At times Cat books are not as explicit as we want to be mechanics would like to see ether. I have been in one twice but way to long ago. Your problem has to be with the reverse idler gearing.

Without getting into parts numbers now, be careful as the earlier 4and 5 R series transmission is the same shafts and case. Engine RPM was different so gears are different. Also possible differences from dry and wet clutch 8 and 9 U tractors. The top shaft is different to match up to clutch's differently. But I think they are interchangeable otherwise. But I am guessing again.

I am thinking the removing and then reinstall are the hardest part.

If I remember right the 4R had a straight roller bearing setup on the reverse idler when they went to the 9U they used double timkens. Much better!

Hello Ray54
Gear train is identical in both the 4R/5R and 9U/8U except for the forward and reverse gears that compensate for the higher RPM. First increases to 1.7 and Reverse increases to 2.0. Apparently the workshop manual in the library is for the older 4R/5R.
Shafts are different as one has a flange and the other has an adapter plate for the universal joints. Correct me if I am wrong but I think that happened at 9U13263.

17AFarmer
Yes that is correct, The older 4R/5R also used the bore of the gear as the outer race of the bearing meaning if the bearing collapsed so did the gear.

With our wide gauge D6 it was prone to input shaft breakage. First time at the collar that locks the first two gears in position and the second and third times the weld broke holding the drive flange on the shaft. First time the weld broke my father had a professional welder weld it up and the second time I welded it myself.. Hasn't broken since.

Finally got to open up the side cover and look inside. On the input shaft , the first gear on the shaft towards the front just spins when in F1-4, . Appears to be stripped splines . No missing teeth or anything other than normal small shavings on the mag drain plug. Got my servicemans book and after reading thru what I have do, and the pullers that I dont have, I would like to talk to someone about getting an estimate to do the repair, or if someone would want to help with the job. Also will need to source parts. Juiceman , you said you may have parts and people that can help. .Can I contact you for more info?

I believe I have all early D6 and D8 trans gears and probably the bearings also. Some gears are new and some used. All bearings are new. When you find out the CAT #s leave me a PM here on ACMOC.

Also wondering if you must pull the other 3 shafts in order pull the top shaft or can it be pulled by itself?

What you need above all is access to an auto crane to pick the trans out of the machine. Makes life a whole lot easier. Once the trans is out, you can do what you have to do to it with basic tools. I really don’t think any magic pullers are actually necessary. Besides, labor rates are way up there in the ether with Elon’s satellites….buy the service manual ala ebay and get after it yourself!

It has been to long since I was in one, but I believe the top shaft is first. They only go one way. I don't remember needing a puller. The only puller of quality I have is maxed out on the pony fly wheel. All others I have are cheap China junk. So no outlandish amount of tools is needed.

Foyd green says to leave a pm to contact him but i dont know how to do that. can you just call or text me?