T 84 Noisy Revervse Idler Gear

[TR BUCK]

OK,

I just finished rebuilding my T84 TM

Started the jeep, and the TM had this noise. in all gears. Sounded like the leading edge of the 1st gear was just bearly rubbing something, or maybe the reverse idler.

I just spend the past 2.5 hours taking the TM out again.

Stripped it down examining all the parts,

No sign of anything rubbing.

When I got down to just the cluster gear and the reverse idler. I could spin the cluster gear and get the sound I was hearing.

Is that a result of bad meshing of the gears????

Cluster gear is new from RFJP the reverse idler has bearly been used, and I do not know where that came from.

[Ben Dover]

There are 5 bolts used to attach the transfer to the transmission , one is shorter and the hole lines up with the Reverse Idler Gear. I believe the long are 1-1/8", and the short lower one is 1" long. Using the wrong bolt will result in the bolt contacting the Rev-Idler.

[tamnalan]

Can you post a pic of your cluster gear?

Wondering if if looks just like the one I posted, with the "long" first gear teeth. My first/reverse slider gear rubs against the first gear on the cluster when in neutral. I can feel it through the first/reverse shifter fork when I spin the trans by hand.

I think you and I are having the same problem.

[TR BUCK]

Joel,

I looked at the bolts as I removed them and none had evidence off contact, Nor any other part had scoring from contact.

tamnalan,

I will post photo soon.

But what I am seeing, is with just the cluster gear and reverse idler in place I can turn the clusterby hand and get this clatering sound.

I can take the reverse idler and wiggle it in the rotation direction, It fits snug on the shaft. But has play in the meshing of the gears.

Something is not right with the cluster and the reverse idler.

[Ed Menees]

Look for this condition. I had this problem once.

[tamnalan]

Thanks Ed - that is exactly my problem.

What did you do about it.. Different parts? Grind something?

[TR BUCK]

Ed,

That is not the case with my TM.

I tried to upload a video of the TM in operation with this noise you can hear. Like a steady clatering .

As in my previous post, I sort of narrowed it down to the cluster gear meshing with the reverse idler.

With all parts out of the TM and just the Cluster gear and reverse idler i can get a similar sound buy turning the cluster gear by hand.

I ordered a new reverse idler from RFJP maybe since the cluster gear came from RFJP the two gears may get along. If not, I do have a few more hairs left to pull out and if I had a cat I would kick it.

[tamnalan]

TR, in your situation, all is ok until you put the shift rail in?

You can "locate" the first/reverse slider gear by hand at a point where it doesn't rub on either the cluster's first gear or the reverse idler gear, but after you put the shift fork, the shift rail, and the poppet ball in, then it rubs?

[David Welch]

If the shift rail has the recess for the neutral poppet cut in the wrong position it can hold the gear against the
cluster gear. I have seen a shift rail that had the recess for the lock out pin in the wrong location that caused the shift rail not to reach the neutral position-- causing this symptom.

[TR BUCK]

That is not the issue with my TM.

I believe it is a compatability issue with the reverse idler and the cluster gear.

I think the gears do not mesh as close as they should.

[tamnalan]

I had the same problem as Ed - the first gear teeth on my cluster were cut too long. I had a fellow with a lathe grind 1/8" off the cluster's first gear and then I used a dremel & small stone to re-bevel the gear teeth. This cured my own first/reverse slider gear rubbing problem - will put it all back in today and pray it shifts!

Here was the problem. My takeout cluster is on the left, replacement on the right. Note that the first gear teeth are cut much longer than on the takeout cluster.



Here's how it came out after grinding and re-shaping the teeth.

[David Welch]

Have you checked that the shifter rail was not the culprit

[tamnalan]

I did check that. I have three of them - my two old ones and the one from this trans were all notched the same.

Hopefully TR Buck solved his problem with the replacement reverse idler gear.

[TR BUCK]

OK here is the poop as of today.

When I disassembled the TM I got down to the cluster gear and R idler gear, with shafts installed I could trun the cluster by hand and hear the clatering noise between the two gears.

On Thursday I received a new reverse idler from RFJP

I removed the suspect R idler and replaced it with the new one, What do you know no noise.

So I suspect a bad R idler gear possible teeth cut out of spec.

Now I need the get the assembly back togeather,

As far as the hair growing back, I think that is a lost cause.

Will post the final results later.


And by the way, I found a shifter rail in a pile of parts that was machined wrong, this was an extra rail I had but never used, It is in the scrap heap now.

[echelon1]

Thanks for the backfeed, we now know bad idler gears are around as well.
What a disaster!!!!!!

Gindi.