Sleigher

Short background-
Original owner of truck.
Rebuilt transmission at 279K. Lubrication issue. Likely caused by low fluid due to cast iron case not holding onto oil. Never did figure out why. When they rebuilt the transmission they installed a new main shaft along with new fifth gear nut. The one with two set screws, two piece thrust washer and a concave washer.
The rebuild was about 8 or 9 years ago.
I now have 314K miles. Driving through the desert last week at 9 pm I lost fifth gear (first time ever).
After a moment of panic I realized what had happened and drove the 300 miles home in fourth gear. I have a GV splitter so it wasn't that bad.
Did a bunch of research and pulled the transfer case. Saw exactly what I thought I would and patted myself on the back for being so smart.
Went out to clean up the area and get ready for my parts to arrive and found a piece of washer in the tail housing?
Spent an hour fishing with a magnet and ended up getting a bunch of washer chunks out of the bottom of the transmission. Also caught the missing set screw that was not in the nut.
None of the repair kits that I saw come with new split thrust washers.
My questions-
1. The repair kit that I bought (actually bought two because the first one seems a little cheap so I bought the genuine Mopar kit with retainer) has the retainer cup along with a new nut and concave washers. Do I need to get new thrust washers too or install without?
2. What does the retainer cup rest against? I know the shaft splines keep it from spinning but does the transfer case shaft just keep it from sliding back and forth?
3. Is the retainer cup the pinnacle of this repair? Seems like it should work well but I'm concerned about the thrust from the main gear.
4. Are there more oil options now for this transmission? I was using Amsoil but Lucas claims that their synthetic works too.

Any other tips. I know this topic has been beat to death but I can't find any information on the split thrust washers.

Thanks in advance.

P

Sleigher

I did have some communication with Torque King.
They said that since I had the fully splined shaft which came with the split thrust washers I needed to go back with those.
I watched a video (well, lots and lots of them) where the guy who was rebuilding his had decided that the washers were simply shrapnel and chose not to reinstall them. I bought them but have not decided 100% on whether or not to reinstall.

The sales manager at Torque King told me that they did not think the retainer cup was the way to go, they don't sell it. Simply that after working on 100s of these transmissions they didn't think it was a good approach. I'm torn on this too.

Still be happy to hear more information.

Thanks

Sleigher

Truck is back together.
I ended up installing the two piece thrust washers.
They are tricky as they want to fall out when you put them in. They come with a retaining washer which keeps them from falling out. The strange part is that the thrust washers are thicker than the retaining washer so once you start tightening the nut the concave washer rests against the thrust washers and the retaining washer never gets pressure.
I thought I had it very tight. I do not know how anyone could get enough torque on the nut with only a chisel.
I purchased the spanner wrench which allowed me to put quite a bit of torque on the nut. Basically using a breaker bar and pushing in a sorta military press fashion (feet braced against my boat trailer).
When I noticed the retaining washer was loose I used a three pound sledge on the spanner wrench until it was starting to spread out. The retainer is still loose but that must be by design as, like I said earlier, the thrust washers are thicker.
I decided to add the splined retainer as well. I don't know how much play it has once the transfer case is in place but I don't think it could hurt.
I ended up going with Pennzoil Synchromesh as it specifically states that it meets the Chrysler MS-9224 spec.
I had some Lucas Synthetic gear oil but they confirmed that it did not meet the spec. They did recommend their 50 wt oil but I wasn't convinced.
Pumped the oil in yesterday and backed out of the shop to get stuck in the snow. One of the vacuum lines had pulled loose. Luckily that was it.
Crawled under the truck, in the snow, and took off.
Only went over the hill and back but everything worked.
Worst case is I'll have to get a new tranny. It's only money.

P

oliver foster

Thank you for the update on the 5th gear fix you choose.
Keep us posted as to how it works as the miles rack up.