The Stovebolt Site Forums The Shop Area Driveline Grinding Noise from T-5

Drove the truck this weekend a good bit and noticed a grinding noise that seems to be coming from the transmission. It is particularly noticeable as I am slowing down in fifth gear, but it is always there, just easier to hear in fifth. As I release the clutch is will stop maiking the noise.
I have no idea what I might be looking for.

How about 3rd gear & 4th? A brg. going bad in a trans. will usually be noisey in the lower gears & O-drive. 4 th is straight through so ther is little pressure on the brgs. If it has a drive shaft carrier brg be sure to check it & make sure the noise is not coming from the rear end. Take a look at the lube in the trans. If it is silver colored you know you have a problem.

Just a suggestion.....you might want to drop the driveshaft and check out the slip yoke and the internal bushing in the transmission tail housing. This bushing is often overlooked and if the slip yoke OD is galled, it will be noisy and this bushing will need to be pulled and replaced. This can be done with the transmission in place. It's critical to keep the T5 full of lube so that this bushing and the slip yoke splines stay lubed.

If the noise is definitely in the transmission and not the differential, it sounds like you're going to have to go for a box rebuild.

Hope this helps..

Dave

Took the truck to a transmission guy. He suggested setting up the T-5 transmission with a rear mount and, as noted in a later thread, I fitted the T-5 with a rear transmission mount located in the crossmember just behind the stock transmission location. The T-5 rear mount crosses right over the stock location of the crossmember just forward of dead center of the crossmember, front to back, and it worked out to a great set up. Unfortunately, it didn't stop the grinding noise and we are still at square one with the noise barely there in third, more in fourth and very predominant in fifth gear. I'll get back with him this week and see what is next.

This subject has been discussed many times but I'm wondering what kind of lube you're using in your T-5? Not trying to hijack the thread or go down a rabbit trail but it is possible that using the wrong lubricant could cause a problem like you're experiencing.

I've seen it posted on the boards here that all NWC T-5's use gear oil and all WC T-5's use Dexron II ATF but that doesn't jive with GM factory information. I have a NWC out of an '89 S-10 and the owners manual clearly states to use only ATF. I followed the advice given on another site devoted to T-5's that states to consult the owners manual of the donor vehicle for the type of lube to use.

Joe,does it make any noise in neutral with clutch released ? I wonder if the front bearing is going bad ?

Tim

When you say releasing the clutch are you referring to pushing in the clutch,did you trim the collar on the front of the trans as it needs to be trimmed some.

I mean in neutral with no feet on the clutch pedal,like you are driving.


Tim

No, it makes no noise except in fifth gear overdrive and ever so slightly in third and slightly in fourth. None with the clutch pedal out in neutral or in, for that matter.
At this point, since a conclusive diagnosis can't be made, I'm tempted to pull the transmission and go through it AGAIN. It makes me mad because it probably has less than 500 miles on it since I put the T-5 five in the truck and the T-5 was rebuilt prior to that install.
It is a NWC T-5, so I used Dexron trans fluid in it as clearly stated in the owner's manual for a 1985-86 NWC T-5, 1352-145.

Joe,when I first installed my t-5 in my pickup,after being rebuilt.I was on the highway in 5th gear and she let loose with a hell of a bang popping out of 5th gear.I tried to stick it back into gear and nothing but grinding in fifth.It also had a slight grinding going into 4th after this happened.I took it back to the re builder and he found that the pin or snap ring come loose on fifth gear.He repaired it and everything has been good since.


Tim

Thanks for the reply, Tim. Was he able to do that with the transmission in the truck, or did you have to pull it?

I pulled it and took it back to him.I don't think it could be taken apart in the truck,just my thoughts.

Tim

I started pulling the tranny today. Hope to get it out tomorrow and off to the man!

Joe,if you would,let us know what is going on with your t-5.

Thanks,Tim

I will be happy to do that.
Still not out of the truck yet, BUT ALL of the Christmas decorations are down and put away!

Tim - I think you may be on to something. The last time I drove the truck, I heard a ping in the transmission when I shifted into fifth gear - I imagine much like the one you describe. I didn't shift into fifth after that - just headed back to the house. I have installed a rear mount on the transmission, as suggested, but the grinding noise was still there.
Today I drained the fluid. It was very red, just like out of the bottle with not a bit of metallic color or gray color or any other sign of metal. The transmission is now out of the truck and ASAP it goes to the transmission man. While it's out, I'm also going to install a Schiefer aluminum flywheel to help things out a little.

As reported in the above thread, the T-5 is out of the truck and I delivered it today to the transmission guy. He asked me what year it was and I told him it was an 85-86 according to the code on the transmission 1352-145. He looked at it closely and told me it was an 88 T-5. He pointed out a star shaped casting on the left top of the shifter tower toward the rear. I was very surprised by his statement and had never heard of that type of number mentioned as an indication of the year of manufacturing for a T-5. So, right away I remember that the T-5's began using an electric speedo around that time, but do not remember what was the first year for an electric speedo. Next I thought it might be a tail from a later model, but if it is an 88, the question still is what was the first year of the electric speedo? Can an electric speedo be switched with a regular speedo? I'm stumped on that one and now wonder what I have???
That's the latest.

All of my t-5s are 1352-145 and according to the info on the net,they are 1985-1986.I believe you can change the speedometer gear and tail shaft from one to the other.I thought 1987 or 1988 was when the electronic speedometer came into place.

Keep us posted on the problem of your t-5.



Tim

Well, I think I gots me a problem! The transmission checked out clear of any problems. I had him put new bearings in it all the way through.
Now I'm moving on to what may be next. Any ideas? Throw out bearing? The transmission guy mentioned the pilot bushing, so I guess I'll change that out. Other than that, I can't come up with anything else that it might be. I will reinstall and see what shows up next, if anything.
I HATE THESE KIND OF PROBLEMS!

Joe,could it be the clutch disc hanging up on the input shaft ? Did you put a new pilot bushing in it from the beginning ? You may have solved it by replacing the bearings,you won't know until you reinstall it.
I'm going to try rebuilding the t-5 I put in my suburban,one of these days.I installed it without checking it out,it seems fine.

Keep us informed !!

hanks,Tim

The fellow who rebuilt the transmission mentioned the pilot bushing as something I should replace. I plan on doing that, but I don't quite understand what you mean when you say "the clutch disc could be hanging up on the input shaft". Can you explain and I will learn something and other might, too.
Thanks for your interest, Tim!

maybe,it's not sliding on the input shaft as it should,hanging up ? just a thought .

Tim

The input shaft splines on some T-5's are too short- - - -the clutch disc gets wedged tight against the back of the spline as the transmission is bolted in, and the disc drags the flywheel, making the gears grind, particularly reverse, as you try to put the trans into gear. The fix is to lengthen the splines back toward the transmission with a thin cutoff wheel on a small hand grinder. The disc should be able to slide freely about 1/2" or so further toward the transmission than it can before the splines are lengthened.
Jerry

Joe,what have you figured out on the transmission ?

Tim

Nothing yet Tim. I appreciate you checking in with me!! I have looked at what Jerry mentioned just above you and don't see any problems, but I am revisiting everything. I have a couple of little things I have adjusted and I intend to keep "picking" at any little thinks I see to be sure they are right. I'm starting with the pilot bushing and going back to the front U-joint. I'll then do a test run and if I still have a problem, I'll do the front and rear U-joints, the differential and the pinion angle, and if I have to the rear wheels bearings. Somewhere in there lies the problem. I think I should find it. I dang sure hope I do!

An update - I have everything ready for a reinstall and in fact have tried four times to get the T-5 in and it won't go. Very tight area to work in and it's going to take a little more time to wiggle her in.

I had to turn the trans side ways to get it in,if you dont the shifter area will hit the floor.

the T5's I had problems with grinding in 5th was bad bearings on the intermediate shaft. Also, drive shaft phasing is critical as I had an out of phase shaft in a project that provided a nasty rattle/vibration at high speed. did you have the driveshaft length shortened at a reputable shop, or did you shorten it yourself.

also, check the output bushing.

This has been a slow moving project. I decided, as I mentioned, to change everything from the front pilot bushing to the front U-joint. I ran into a problem with the throwout bearing. The one that I had in there is a BCA 697-22. It might not be bad, but I would like to replace it. Does anyone have any information on where I might find this bearing? Thank you!

Joe, I'll see what cross reference, or actual number I can come up with tomorrow. No promises but the parts house does have a couple places we can call!

Alvin -
Any help is appreciated! The problem now seems that you can't buy a throwout bearing unless you buy the "clutch kit", which, as I'm sure you know, contains a pressure plate, alignment tool, throwout bearing and a clutch disc. All I need is the throwout bearing.
Joe

Try buying just the bearing from a dealer. I doubt if the whole assembly was required when those transmissions were new.
Jerry

Any parts store should sell a TO brg. by itself. If you cant find one let me know. Ill send you one.
george

Joe, I shot you a response in General Truck. yes, you can get them seperate as George mentioned but I just need a number. Check out the post back in General.

Gosh, Alvin - Thank You and The Lady at the store for the fine work.
I, too, have been trying to research the matter. I found a BCA throwout bearing on ebaY, which claims it is a direct replacement for the Master Parts Catalog Number 909422, the orginal Part Number. I also found another one on ebaY that is a Delco product that the lister claims is a direct replacement for original Part Number 909422. The first one I acted on because the picture of the bearing looked correct. The second one is located in Ronoake, TX just north of me about 15 miles. I have contacted the lister and I am going to see him tomorrow with my old one in hand to do an eyeball comparison.
One of these two bearings should work and the second, if it works too, will be a back-up. Apparently a back up is now necessary on this particular part with the obvious problems involved in finding one of them. If all this fails, I will have to fall back on your discovery, which I am greatful for.
Thank you for the help and I hope I didn't cause the Lady at your work with too much of a problem.
I'll let you know how tomorrow goes with the Delco product.