I recently rebuilt my t56 and now have some problems. I replaced the 3-4 syncro assy, rev syncro assy, all blocker rings, all bearings, all fork pads, all seals, isolator cup, and reverse gear. After everything was back together, it grinds going into 4th gear. It will still go in and stay but just grinds a little bit as it is going into gear. Everything else worked perfectly. Then all of a sudden, I went into 3rd gear and it did the same thing. I didn't think much of it until I couldn't get it to come back out of 3rd gear. It was somewhere between 3rd gear and neutral. It acted like it was in neutral but it was stuck. When I finally got it working again, I continued shifting like normal. So I tried 4th gear again and it did the same thing. Stuck somewhere between gear and neutral. What is going on? is it getting hung up on the blocker rings or something? I am only having problems with 3rd and 4th and they are side by side and share a syncro assy. Is it a must to feeler gauge everthing while assembling? Sorry so long. Any help is greatly appreciated.

 

it's always best to question the easy things first. make sure the blocking rings and collar are on correctly. being backwards or not stuck on enough can cause these types of problems. You can isolate the problem to synchronizer assembly since it is between the 3rd and 4th gear assy. they do use the same assembly. you can virtually eliminate any problems with the gears themselves. since 4th gear is directly connected to the mainshaft in the t-56, you can eliminate posibilies of the mainshaft being out of spec. i can see only about a 10% chance of anything else being wrong besides the assembly. if the synchro assy was installed correctly, check collar wear for signs of fitment. if too loose or too tight, something could hang up or not engage correctly. unfortunately, these types of checks must all be done with the trans apart and on the bench. and unfortunately, it is a more difficult tranny to remove and get apart than some RWD Manual trans. good luck, keep us in touch

 

Come to find out it was the spring on the syncro assy that came off. Not sure what caused it but it is back together now and I will be testing it either tonight or tomorrow. Is there a certain way the syncro assy goes on? It was brand new so I couldn't tell which way it went.

 

Well I got it back together and tested it. The same problem is happening. It is grinding going into 4th. Everything between 3rd and 4th gear is brand new so I don't know what is going on. Does anybody have any idea?

 

Somebody told me that the only way the spring could come off is the syncro overextending. Does this sound right? If so, what could cause it to do that?

 

I know there has to be someone out there who has run into this problem before. Please...any info might help. I pulled the tranny out tonight and it will get tore down again tomorrow.

 

I have never had it happen and do not think it will if the spring is installed all the way down like it should sit. I had a guy in Conroe that rebuilt his and the same thing happened. Come to find out he did not have the spring on right. If you need pictures let me know. I will be happy to send them over.

Check the gears for burrs also. You need to look at the slider teeth on the gear and make sure they are not chewed up. That causes the problems you are having as well. If they are you need to replace the gears or it will happen again.

Thanks,
Joe @ T56Rebuilds.com

 

Thanks for the replies. Come to find out, we are a couple of jackasses. The forth gear blocker ring, that goes directly on top of the forth gear/input shaft, was never installed. Somehow during the first time we built it, we forgot to put it on. Every time after that, it just seemed like it wasn't supposed to be there. Luckily it didn't do any major damage from the syncro spirngs and keys coming out. All I have to buy extra is a new set of springs and keys. Dumb mistake but we got it figured out.