The Stovebolt Site Forums The Shop Area Driveline Bearing whine in 5th gear?

Here's the scenario, I have a t-5 world class 2.95 first gear transmission in my truck. Recently started whining in 5th gear, not a sound in other gears.I pulled it out this morning and was going to replace it with another transmission, but have to change the clutch disc. So after removing the clutch I found the input shaft bushing in the crankshaft is not round anymore (put an old input shaft in there and can move it side to side, and up and down).

I will change the bushing, do you think this may have been the reason for the whine in 5th gear? There doesn't seem to be any abnormal play in the transmission. Oil looks ok, what are the chances of this not making the whine in 5th gear now. Should I just put the other transmission in. Thoughts ??

1959 1/2tn with a 261

If it only whines in 5th, which is an indirect gear, one needs to look at the bearings that are active in that gear. If the pilot bearing on the input shaft has lot of runout, the countershaft will propagate that runout to everything else. What kind of operation caused the pilot bearing to be worn that way-seating the trans by tightening the mounting bolts with the trans not lined up carefully, not using guide bolts, will broach a groove in it.

Hard to tell if that was the cause of whining, will never know unless putting it back in.

Ed

When I installed the transmission I used two 6 inch long bolts with the heads cut off, in the top holes of the bellhousing. However I didn't check the bushing at that time. It had been together and running for 8 years with the old three speed transmission. The t5 has only been in about a year maybe 1,000 miles? I have noticed the whine has gotten progressively louder, that is why I removed it .

does the noise change under load, decal, coast?

I really haven't driven the truck much the last few months, and can't recall when I here it more. I think under load only in 5th gear, 1st thru 4th not a sound, really a sweet little transmission.

Hi Tommy. Hope it is cooler in Metairie. Wish we'd known about this before you pulled the transmission...but from here I'd guess it is the input shaft bushing. Although it possibly could be the throwout bearing. One way to check these is to push the clutch in all the way, keep it down and then shift into neutral. If the noise continues, the throwout bearing is failing. If the noise stops, the source is the input shaft bushing (and I will tell you why in just a moment). However the throwout bearing makes a sound all its own.

Why do I say it stops when the clutch is in? When the bushing wears as you've described, it lets the input shaft move around in an "off-center" manner...I don't mean to say it bounces around all the time, but when you shift into fifth it can stop moving anywhere when you let the clutch out. At times it may be centered and at times it definitely won't be. And this will cause the shaft to wobble around some inside the transmission and when it does you can and eventually will get all sorts of weird noises. I always noticed it more in the top gear and I decided it was because that gear can have less acceleration stress on it at times and it is at those times it will start howling and whining the most. Once it starts I think it is normal to let off the gas and listen and that can actually make it howl a little more. When you push in the clutch, you free the shaft and it no longer is running in that same "wobble" pattern. So the noise will stop.

The good news is those are cheap and easy to replace.

Hey Jon,
The heat index earlier was 105, now is 100, glad I have a/c in the garage. I'm going to change the bushing and put a new clutch and throw out bearing in. Think I will put the other t5 in, it has mechanical speedometer instead of the electric one. So I will have a speedometer instead of gps that doesn't work all the time, and have an odometer.

Yep, we had something like 104 here inside the loop, Tommy. I wish I had a/c in the garage but just an old fan. However there is a fridge with some PBR in there. I have a strong suspicion your noises will vanish. Hope so anyhow. If you run across a mechanical tail section, let me know. The one I have is electric.

I'll keep an eye open, I just stumbled across this one in a pull a part yard and grabbed it. It has I think a 3.76 first gear, will see how it works out with the 3.90 rear. But at least I'll have a speedometer and odometer again.

Thanks. I recall one of the T5 models had a 3.97 first. Mine has a 4.03 first. With a 3.90 rear that's going to be a strong starting line ratio. You could hire out pulling stumps. I'm going to hit the hay now.

Good Sunday morning to everyone, I want to tell ya'll a story about pilot shaft bushing removal. I will preface this with the fact that the bushing was not round anymore. I used a piece of steel rod that was to big for the new bushing but fit just right in the rear most part of the old bushing. I believe it was 5/8 but not sure. I first tried damp whole wheat bread which was a dismal failure.Sure glad I didn't use wheel bearing grease ( picture Gallagher smashing water mellons). What a mess. So I was thinking how am I going to get this done? Well as I'm sure most of you know here in South Louisiana everything revolves around food. I was at the store and it suddenly hit me as I was walking past the frozen food dept. Pillsbury Grands biscuits!! Gabbed one container and went home. This morning out early to the garage with biscuits in tow, (uncooked) I removed one from the container and proceeded to insert into old bushing. Packing it in as best I could ,then inserted steel rod into biscuit and with a few smacks with a" Maximum Force Adjusting Tool," (BFH), The old bushing was removed with no mess. New bushing installed and hopefully tomorrow the old shoulders will not be hurting as much and the transmission will be replaced and truck back on the road.

The moral to the story, Sometimes you need to think outside the box when you have a problem. I never heard of using biscuit dough to fix anything other than a good place to put some butter. I also thought about using childrens play dough, but no kids around here and that stuff is expensive.

If the end of the main shaft that fits inside the input shaft is badly worn, then the pilot tip will want to wander and cause the pilot bushing to wear quickly. This is true even if the shaft endplay is zero. Fifth gear on the main shaft is outside the case. Thus, it uses the rear case bearing as a fulcrum. First through 3rd gears, being INSIDE the case do not have the same leverage. Fourth is direct drive, so no leverage there.

Also, if the main shaft bearings (or counter shaft bearings) are badly worn, I think that would cause it to whine. Especially so in 5th gear, but I’d think all gears would whine a little.

If your T5 has not been inspected and the whine continues or comes back, you’ll need to open and inspect it.

Biscuits and gravy with the rest?

Jay,
The end of the shaft is perfect, the new bushing fits on it like a glove. What I think the issue really was,when I rebuilt the engine 15yrs ago, the old bushing never got changed, and the engine was out of a school bus, so heavy usage. It was probably worn out when I put it back together. The old 3speed was never quiet, and I just figured I would replace it . Took longer than I figured as I was enjoying the truck. Last year I put the t-5 in and it made a little noise but I just figured I could live with it. Haven't driven it much in the last few months and last time I went on the highway i said we gotta fix this. Will be going to cruisin the coast in october and wanted to fix before then. I'm putting a different transmission that has the cable drive speedometer. Will look into the other one later.

Martin,
I should have cooked the other four biscuits before I went out to work, but didn't realize I would only need to use one.

Tommy,
Yes, your pilot bushing may have needed replacing years ago.
However, I’m not suggesting that the input shaft pilot tip is bad. That’s an easy thing to check as you already mentioned. Just slide a new pilot bushing on the tip and see if there’s any play. Done!

Instead, I’m referring to the tip on the main shaft INSIDE the case. The main shaft tip is machined to fit perfectly inside the 15 roller bearings that live inside the input shaft. If the main shaft tip is heavily worn, then there would be play under load. Not end play, but radial play. The only way to inspect the end of the main shaft (inside the case) is to remove the input shaft and put a micrometer on it. Some are worn badly enough that the very end appears rounded instead of having a nice 90 degree cut.

Anyway, sounds like you have a plan.

Jay,
I realized what you meant, I will get into the one I removed and check the main shaft and bearings later on. I should have taken it apart when i changed the tail housing to an s-10 tail housing. When the cover was off everything looked nice, so didn't bother. Sometimes things come back to grab you by your backside.

Update on transmission.
Well, I changed the transmission to another t -5 with mechanical speedo, now I have a speedo that works. (yeah)! However I'm not thrilled with the 1st gear ratio, I could pull a house down the street at idle. Changed the input shaft to the jeep ten spline shaft and everything is nice and smooth and quiet. I'm happy with that. Thanks for info Jay.
I will be taking the world class T-5 apart to see what the problem is. The question in my mind is ,If I need to replace the main shaft is that part available?



Thanks for the help with this Lugnutz, and everyone else that volunteered info.

I might have a main shaft. Do you need WC or NWC?

Jay,
It's a WC out of a camaro, but I haven't taken it apart yet. Will try to get to this next week, will let you know what I find.

Thanks

Ok. I have a WC T5 main shaft in a shop drawer. Let me know.

The simpler, quicker way to remove a pilot bushing is to screw a threading tap into it, and keep turning when the tap bottoms out in the crankshaft counterbore. The tap will walk the bushing right out of the crankshaft, easy peasey! I believe a 5/8" tap is the one you'll need.
Jerry