Calling Transmission Gurus - ISSUE FOUND!

[Dzimm]

Anyone here familiar with the internals of an automatic trans?  Specifically for a 98 Suzuki Sidekick or Chevy Tracker.

 

I was at the farm today having a blast with the family on the off-road toys.  Went off the ramp for about the 20th time that day and flew real high and far, came down nice and level, felt like all wheels landed together.  As I was driving away from the landing I could hear a grinding noise.  It still drives normal but once it gets above about 15mph it starts to make a terrible grinding/rubbing noise that you could almost feel as well.  It sounds like it's the transmission and I couldn't see anything obviously wrong underneath, granted it was caked in mud and I didn't completely crawl under it.

 

Any ideas on what else it could be or what kind of damage could be going on in there?  I'm also curious how rebuildable it would be with a grinding noise or would I be better off sourcing a replacement?

[jdog]

In all of the gears? My thought would be either drives shaft related or differential. I'd see if it does it in shifted into first gear. Other question is does it get worse the faster you go

[scaleless]

Not an expert, but I've torn a bunch apart.  A constant sound irrespective of the current gear isn't usually something you hear except in transaxle arrangements where the final drive gear has a few chipped teeth.  A chipped tooth in another gear would cause a similar vibration only in that gear - if the broken tooth  was bouncing around other gear sets however, the results would probably be more catastrophic than a vibration.  It's possible the sound is unrelated to the jump, though - burnt or low fluid usually causes noise as well, so you may want to check before you start tearing things up.

 

But that's all if you're sure it's the transmission.  I agree with jdog - I think it's much more likely to be elsewhere in the drivetrain.  Just as an anecdote, my father took his Tundra offroad a few years back and cracked a u-joint cap on the driveshaft and it caused almost identical symptoms to what you're describing.

[Pete M]

get it up on stands and put it in drive so you can walk around and further isolate the noise  

[Dzimm]

Well here's hoping it turns out to not be transmission related.  It was running fine all day until that last jump so I figured it has to have broke due to that.  I didn't do any real troubleshooting yet, was trying to limit damage and it was the end of the day so we were packing up.  I'm going to see about getting it to my house so I can get it cleaned off and spend some time with it.  

 

Thanks for the input!  I'll try to get out there again soon and do some testing in other gears just to see what it does.

[Dzimm]

So we got the Suzuki hauled to my house today so that I can start doing work on it and while strapping it down I spotted the problem..

 

Picture to come

 

The front diff housing exploded!  These are aluminum diffs and they seem to be prone to breaking.  There is a steel upgrade I may look into unless I can find a cheap stock replacement.  I'm hoping it didn't destroy the gears but we'll see how bad it is when it's torn apart.  

 

Also thinking it may be a good time to regear for more torque since it's pretty sluggish off the line.  It can outrun the side by side at speed but gets destroyed by it off the line.

[Pete M]

and so ends the cheap time with the free toy.   time for upgrades!

[Dzimm]

11 minutes ago, Pete M said:

and so ends the cheap time with the free toy.   time for upgrades!

As it always goes!

[Eagle]

6 hours ago, Dzimm said:

The front diff housing exploded!  These are aluminum diffs and they seem to be prone to breaking.  There is a steel upgrade I may look into unless I can find a cheap stock replacement.  I'm hoping it didn't destroy the gears but we'll see how bad it is when it's torn apart.  

 

 

"It's not the fall that hurts, it's the sudden stop at the end."

[Dzimm]

Snapped a picture of it, definitely a  broken tooth on the pinion gear.  Time to rip it apart!