Overdrive install problem

Installed the new overdrive I bought from Herm. I followed the instruction carefully, noting the measurement between the cluster and the case. The measurement was right. After having a tough time with the linkage. I found that it doesn't want to shift fully engage into direct drive. I'm going to give Herm a call tomorrow. Until then. Anyone have a similar problem?

 

Check the synchronizer (blocking) ring. Probably stuck on the cone part of gear out of index with the dog teeth. This will keep the sleeve from engaging the teeth.


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Yep, this. If you tried to put it into drive while you were parked this is likely the problem. Pull the OD housing off the T/C and I'll bet the synchro ring is stuck on the taper of the bull gear. Pull it off, scuff up the I.D. of the synchro with some emery cloth and put it all back together. Put the thing in OD and leave it there for 500 miles for it to break in. After that, when you want to downshift from OD to Direct, it helps to "double clutch" the downshift.

 

I never did put it into direct drive while parked. I drive it in overdrive. That's when I noticed I didn't have enough throw in my shift linkage. After fixing the shifter and linkage. I was idling in the garage. That's when I tried to shift into direct drive. It pops out of gear with the slightest clutch engagement. So is it a break in thing or do I need to take it back apart?

 

Come to think about it maybe I did when I was checking the linkage.

 

What oil are you using? As crazy as it sounds I had simular problems with the synchronizer with GL5, I put GL4 in and problems went away.

 

Oh yes, I don't like the results of GL5 for shifting an OD. GL4 works much better, I think the theory is that GL5 is too slippery to allow the synchro blocking rings to grab the cone on the gear.

Don

 

I called Herm. He said the Barrel gear need to be shimmed out. There's not enough engagement. He's sending me the shims in the mail.

 

What did he say about the oil? GL5 or GL4?

 

I didn't ask about it. Not an issue in my case.

 

I haven't received the shims yet, but I did get the shifter boot.

 

Today I took off the overdrive. I measured how far the barrel gear is sticking out of the case. The instructions said to verify a measurement of .677. I get .696. Could this be my problem?

 

I installed some shims behind the barrel gear, on the main shaft. This helped. I can drive it in direct drive, but when I accelerate or drive up a hill. It will pop out of gear. Looks like I need to add more shims. Herm is sending me some more.

 

After removing the overdrive. I found that my shim pack that I put in earlier is a little to much. Something is not right. I'm thinking the main shaft in my SM465 is the problem. I wonder if I left out a snap ring when I rebuilt it years ago. Maybe the one on the main shaft output bearing. I'll have to take the overdrive off again and check.

 

I found out my main shaft has a lot of play in it. Looks like a rebuild is in order.

 

Took the transmission to get it rebuilt today.

 

Received the rebuilt transmission and installed it yesterday. I'm just waiting on gaskets to finish the install. I'll get back to you after I'm done.

 

I installed the rebuilt transmission, installed the overdrive and it still pops out of gear. I just don't get it. I put all the shims I could under the barrel gear without it binding up. Seems there isn't enough engagement. May have to ditch the idea of having an overdrive.

 

You going to Puyallup next weekend? If so, look me up. You know where to find me. May be able to give some suggestions.


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