sm654 acting up (1 Viewer)

[TLCHopII]

Hello all,
The sm465 is producing "unusual" noises and vibrations when in third gear under power only. If, in third gear, going down hill under engine compression braking there is no noise or vibration.

What could this be?

Background:

1. vehicle has been laid up for about a month, sitting level in the driveway. This was due to a rear spring flip, exhaust system reconfiguration, and all the related changes.
2. Drive shaft replacement is pending.
3. Drove on the road for apx. 3 miles. Parked, nose up on a 30* incline for apx. 1hr. No issue to this point.
4. Got in and 1rst time hitting 3rd it was apparent that there was an issue: Sounded like the gears were not meshing properly and the stick had an unusually strong vibration!
5. 4rth gear is not effected.
6. No vibration or noise: with the clutch pedal depressed; t-case engagement has no effect;
7. Again this only happens in third gear, under power.
8. No issues in shifting in or out of any gear.

Look forward to any help that can be rendered.

 

[jcj_78FJ40]

I know that spring clips retain the third gear on the SM465. The clips are prone to wear and allow the gear to "walk." Most rebuilders replace the clips with a bushing.

Some more info here
SM465 Transmission Rebuild - Specifications - 4-Wheel & Off-Road

The symptom is usually the tranny jumps out of 3rd gear. Maybe you have another issue.

Good luck!

 

[pbgbottle]

i had the 3rd gear problem , c-clip wore out and dropped down and went through the gears and chipped some teeth , upgraded it to the spacer or bushing. and all has been good since ,before mine broke it was also kind of hard to shift into third. not sure why. mine did jump out of gear. but i don't remember vibrations .
it was a long time ago tho



Jake

 

[TLCHopII]

Thanks for the input.
Interestingly, I have not had it jump out of gear even once!

What is really puzzling is the sudden onset of this problem. Guess i'll pull the top end and see if there is anything amiss.

Any further in site is welcome.

 

[TLCHopII]

It seems there is a rebuild in my future.
Pulled the stick today. discovered cracked tack welds and severely worn roll pins. fixed and/or replaced each. Shift gates are much more crisp!

Little effect on the loud noise produced while under power in third gear. Will order/locate a rebuild kit with snap ring eliminator in the morning.

 

[73fj]

When I decided to rebuild mine, I found a handfull of roller bearings in the bottom of the case from someone elses attempt. They looked like the bearings for the input shaft. Maybe theres something floating around in your tranny too.

 

[TLCHopII]

Very likely! When the stick was pulled it seemed that one of the roll pins could very likely have shed a shard or two.

This evening, the many various items were pulled to gain access to the bell housing and transmission top plate. Yet more surprises; on the drivers side near the front of the cover assembly, there is a missing bolt that would seem to act as keeper for the third gear shaft. Judging by the significant debris build up, this bolt and one of the cover bolts have been missing for some time!

Determined that removal would wait until tomorrow after work and the rebuild for either tomorrow night or Sat. Should be interesting. Now I just have to remember to bring the calipers and bearing pullers home with me! At times this is the most difficult of tasks! LOL

 

[TLCHopII]

Altighty then! Just confirmed one of the circlips failed in the third gear drive train. Damage is minimal. Will be reassembling in the AM.

Thanks for all the help!