IFS front diff clicking

[BCRC84]

So I did the overdrive upgrade, and after doing so my front end developed a clicking sound. Everything is still working fine, it doesn't slip when I hold either wheel, everything feels normal. The only other symptom I can see is the spur gear has a slight wobble to it. I've rechecked the transmission twice now and everything's lined up as well as just tight enough.

I can't get into the diff as I have a stripped screw head and no tools to remove it at the moment. If it helps here's a video of what it sounds like https://youtu.be/HKmLrrOacLw

 

[soze]

If you're sure it's the front diff clicking, see if it clicks without the transmission hooked up. It could be that the diff needs to be shimmed. Check to see if there is any difference when you rotate the driveshaft while pulling on it to move the pinion away from the ring gear, and rotating while pushing towards the ring gear. It's possible that you might have a bearing failure on the pinion gear in the diff too.

Also try rotating in both directions to see if it only happens in one direction.

 

[BCRC84]

It does it without the trans attached and in both directions.

 

[HumboldtEF]

I think the real question should be how do we help you get that screw loose.

Where is the screw in question?

The first thing that comes to mind is using a small cutting disc to cut a slot in the head and use a flathead screw driver. Theres screw extractors or the technique of just cramming or hammering in a slightly bigger bit in, either a hex or a star drive.

I think you might be able to test the diff by holding the driveshaft in place as you spin the wheels, if it slips its the gears for sure. The gears do sound like the problem but didnt sound too far gone so I'm not sure that test will work. But like I said you really need to get into the diff and have a look.

 

[BCRC84]

It's one of the bottom screws on the front skid, I just have to find someone with a Dremel I can borrow. I've tried holding the front tires like they would be if they were bound up and didn't feel anything slipping both under power and without a drive shaft attached.

 

[Gula]

Have you checked the set screw for the pinion on the motor? That hitting your spur would make a clicking sound.

 

[BCRC84]

It's definitely not the pinion on the motor. I double checked and disconnected the driveshaft from the transmission, the front end was nice and crunchy while rotating the wheels in either direction, there was absolutely no slipping of the gears. I'm beginning to think I just got unlucky with the bearings that got used.

 

[BCRC84]

I got into the diff, all the bearings felt fine, no noticeable chipping or gouging on the gears, there was a metal shaving inside the diff on the ring gear by one of the bearings but I couldn't locate it's orgin. It's still cclicking..... I'm not sure what direction to go now.

 

[HumboldtEF]

If you found shavings the gears have been slipping, I assume the grease was turned black too.

Personally I'd consider replacing the diff housing or shimming the gears. Its possible the diff housing is a bit out of shape which can potentially lead to something like this. I guess another possibility is if the diff clam shell housing wasn't screwed tightly together it could be letting the ring gear to move allowing the gears to slip.

 

[BCRC84]

Everything was tight on the case, there was some black grease in there. Found the shaving on the ring gear. Do essentially I got screwed and its not even going to be worth the warranty claim since I live in Canada and it'll not only take forever to get up here I'll likely have to pay duty. I kinda feel like I just wasted a lot of money.

 

[BCRC84]

I grabbed some pictures of what I am seeing, hopefully this helps. From my untrained eye everything looks normal, I see absolutely zero damage to both gears or any of the bearings. I did wipe away the pile of grease at the end of the pinion and it looks normal.

https://photos.app.goo.gl/fSFadgYL3KXhJ23i7

I really appreciate all the tips and help. I ran it again for about 10min last night and noticed the clicking was about 80%better, didn't see a loss in power or climbing abilities, it was even able to get out of a few tight spots with no issues.

 

[svt923]

It has been my experience that whenever the axle gears skip, you have damaged the teeth of the gears. It may be minor damage that will still let you drive, but the likelihood of more skipping and damage is much higher. I would plan on getting a new set of axle gears in the near future

 

[BCRC84]

Well that will be fun, local shops don't have any in stock. This will be my last Element, gears shouldn't have been damaged after 2 drives and not abusing the truck.

 

[BCRC84]

Does anyone know of a different ring and pinion set up that will work? I'd rather not replace the junk that broke with more junk.

 

[soze]

Try this out. The diff gears on the element can be reversed. So try putting the diff gear in the opposite direction so that they clench together (since they are helical gears) when accelerating rather than pushing away from each other.

You'll have to do this in both axles, and change the rotation direction of your motor.

 

[BCRC84]

That's brilliant, I had time to just swap the motor wires around, it sounds like that alone solved the problem I don't hear anymore clicking, and it looks like there's more power. It was red to black and black to red before I changed it. Whoever put my rig together was having an off day.

 

[BCRC84]

I'm just wondering if I should clean off the factory grease and re do it? The only grease I have on hand is white lithium is that ok to use?

 

[HumboldtEF]

Yeah it would probably be best to clean out the old grease and any potential debris.

Great Idea Soze! that crossed my mind too but I wasnt sure If it'd help or make it worse. It does sound like they may have installed the diff gears backwards. IIRC ring gear teeth can vary in strength when driving one side of the tooth vs the other (depending on the design).

I dont have any experience with white lithium grease on plastic but not all greases are safe to use with plastic and rubber. I believe its petroleum based so my gut says its likely not the best but again I dont know. Definitely check any info the manufacture might have on it.

 

[BCRC84]

I've got all metal gears in my diffs thankfully. I'll have to pull it apart to clean it anyway.

 

[HumboldtEF]

But the diff housing is plastic.

EDIT: heres a somewhat recent thread with folks saying Lithium grease is fine http://www.rccrawler.com/forum/general-crawlers/617418-gear-grease-@-auto-store-hardware-store.html