TR-3550 input shaft question

[VTStang66]

I usually hang out in classics, but I figured you 5.0 guys would probably be a better choice for this one. I have a tremec 3550 in my car, and it's been in there for 2 years (almost exactly) with no problems. Very recently I started getting a noticable vibration right around 2000 RPM in every gear. I can feel it most in the clutch pedal and the shifter. I'm pretty sure it's not the engine because I have a fluidampr and there's not much that can change in the engine balance if it was right in the first place.

I have a lakewood scattershield and when I put it all together I didn't check to make sure it was all centered like you're supposed to. I just put it together and it worked fine for 2 years. I'm afraid I might have messed up the input shaft though, if it's not really centered like it should be. I pulled the tranny and there is a little play in the input shaft. The splined part moves around just a little inside the outer tube (I can wiggle it back and forth). I didn't pay attention when I put it in, so I don't know if it always did that. Does anybody know if it's supposed to be perfectly tight in there, or if it can have a little play? And if it is messed up, how hard is it to fix? Can I just buy a new input shaft and bolt it in?

 

[jrichker]

No.

You will need a dial indicator to set the endplay of the input shaft.

I don't know how you feel about the DYI thing when it comes to gears, some people don't like the idea of working on transmissions. If the DYI transmission fix idea isn't something that you would rather leave to someone else, here are some resources:

See http://www.ttcautomotive.com/English/onlineorder/product.asp to download a FREE service manual for T5 or Tremec 3550
You will need the Adobe Acrobat viewer which is also a free download – http://www.adobe.com/products/acrobat/readstep2.html

See http://www.hanlonmotorsports.com/ or http://www.ddperformance.com/index2.htm for parts

http://cartapes.com also has a video on how to rebuild your T5 or Tremec. It costs less than $20, and is worth every penny of it.

I did a Tremec 3550 rebuild, and it wasn't that difficult. The video was an immense help, and I would recommend viewing it. At $20, it will give you an opportunity to look and decide for yourself if you think that it is something you want to try to do.

You will also need a magnetic base and dial indicator to measure the endplay ($20-$140). http://www1.mscdirect.com/CGI/NNPDFF?PMPAGE=1290&PARTPG=NNLMK32

The tricky part is that you will need some shims to adjust the endplay in the two shafts: the new bearings will change the clearance. There is no way of telling what it will be until you get to the point that it is time to measure and check the clearances. Halon has the individual shims if you can wait for them. If you can't afford the wait, the auto parts store can sell you some shim stock and you can make your own, or have a machine shop make them for you. The shim stock comes in brass (easy to cut) and steel, in varying thicknesses. That's where the dial indicator & base come in - there is no way to get the clearance right without it.

Getting the car jacked up high enough to get the trans jack in and out from under the car was somewhat challenging. Since I didn't have a helper, getting the trans out of the car and back it was one of the more difficult things about the job. I built a trans jack out of 2x6's, some angle iron and a $25 floor jack. If I hadn't done that, I would have needed a helper or to rent a commercial trans jack. At 100+ pounds the Tremec 3550 was far too heavy for me to lift by myself.

 

[VTStang66]

Thanks for the quick and thorough response, but I have some questions.

What is DYI?

The tricky part is that you will need some shims to adjust the endplay in the two shafts: the new bearings will change the clearance. There is no way of telling what it will be until you get to the point that it is time to measure and check the clearances. Halon has the individual shims if you can wait for them. If you can't afford the wait, the auto parts store can sell you some shim stock and you can make your own, or have a machine shop make them for you. The shim stock comes in brass (easy to cut) and steel, in varying thicknesses. That's where the dial indicator & base come in - there is no way to get the clearance right without it.

What 2 shafts, and what new bearings? Do you think I'll need a new input shaft?

 

[jrichker]

The input shaft has a shim pack that fits between the outer bearing race of the input shaft roller bearing and the input shaft housing.

The other set of shims is only needed if you replace any of the other components on the countershaft, such as the bearings or countershaft itself.

I highly recommend that you download the FREE service manual if you haven't already done so. It will explain the process in much more detail & accuracy than I can in the time & space here on Stangnet.

The $20 video is a bargain if you really want an expert to do a step by step explaination on how to do it.