Yamaha+Toyota=Fun

I dont know if this fits in the Fab section...

Anyways I just bought a used 3rd with 4.88 gears. I noticed that after I installed it my truck will clunk every once in a while when shifting or if a tap the gas a few times. Ive done some searching and come to the conclution that my backlash is a bit too lose. From what I have read so far it doesnt seem to hard to do. I have all the neccesary tools to do it, I just need to find a write up of some sort so I will be 100% sure on what I am doing. If anyone has any tips or links it would greatly be appriciated. Also if I drive the truck when its like this can I cause any serious damage to my ring and pinion?

Thanks

jimbo74

if the gearlash is not set properly, it can easily damage the gears... the msot common is damage is shearing off of teeth

Yamaha+Toyota=Fun

From what I have hear having a lash that is too tight is what damages the gear in most cases. Too much heat/friction is generated from this.

midiwall

Both are right (too loose or too tight), which is why it's a job best left to those folks that have done it a few hundred times.

superjoe83

how many miles are on these gears?, setting backlash is very easy, all you need is a dial indicator, and a spanner wrench helps also, are they quiet or noisy (other than the clank)

Shane

Not exactly, there's no fabrication involved... This is tech...



Is there a locker of any type in this diff by chance? After you installed the diff and before you crawled out from under there did you happen to take the time to regrease the driveline including the slip joint? Was the pinion flange tight? Did you tighten all the driveshaft bolts?

Yamaha+Toyota=Fun

Everything is tight on the drive shaft, yokes, pinion flange, etc.... im pretty sure its the backlash. Everything was regreased a day after.

The gears a quite, they do not make any noise except for clank. I dont know how many miles are on the gears, but when it was out they looked like they were in pretty good shape(no chip, pitting, pealing, etc).

What I need is just a write up on exactly how to do it. I have all the tools, I have an idea what im doing, I just dont know the exact procedure, and on something like this it kinda neccesary to do it right the first time. Would it be in the FSM?

*edit* no locker in the 3rd

mt_goat

Here's one link: http://zukaz.tripod.com/gearpatterns1.htm

mt_goat

I like this one too: http://www.precisiongear.com/pgtechpatterns.htm

mt_goat

This one may help too: http://www.usgear.com/ring__pinion_installation.htm

Yamaha+Toyota=Fun

will i need to check to contact pattern after adjusting the backlash?

Thanks for all the links mt goat!!

mt_goat

I'd check it before, that's how you tell which way to adjust it, if it even needs adjusting. Looks pretty easy to check, I've never done it though.

Yamaha+Toyota=Fun

I still cant figure out exactly what I'm suppost to do. Everything I read just sayes something like "now adjust the backlash by turning...." etc. I just dont understand where I take the adjustment from, am I suppost to hold the pinion flange and turn the ring gear? Maybe I should just have someone else do this for me....

ZUK

iTrader: (1)

You have a dial indicator with magnetic base right?....cause if you don't, there is no sense in messing with the BL. Go to my website if you want pics of backlash adjustments. ZUK

ps--I doubt the BL is the reason for the clunk....it would take some serious BL to be noticable.

Yamaha+Toyota=Fun

Yeah i got a dial indicator. Im pretty sure its backlash, I can rotate the pinion flange on the 3rd a pretty good amount while holding the ring gear. What else would it be besides the BL?

Thanks,
Austin

mt_goat

Well me helping with this is kind of the blind leading the blind, but as I understand it you adjust the BL by taking it apart and putting in different size shims until you get a good paint pattern.

ZUK

iTrader: (1)

You now have 488 gears and that means 20% more torque....maybe you have axle wrap. Do you have thin leaf packs or blocks? Maybe the u-bolts are loose.

Yamaha+Toyota=Fun

My springs are pretty soft, but they are stock. ill check out the u-bolts tomorrow.

ZUK

iTrader: (1)

while you're checking the u-bolts.....see any 3 or 4 inch blocks in there?

Yamaha+Toyota=Fun

lol... no blocks. I just installed some add a leafs and I think that solved the problem. I havent heard the clunk since then.