differential spider gears

[mrbreeze]

Does anyone know how much clearance is considered normal between the back of the spider gears and the carrier thrust surface on a mid 90's chevrolet pick up truck differential? Also if the spider gears have to much end play at the thrust surface would this cause a whine to come from the differential?
Thank you in advance for any help.

 

[GregLocock]

Second question first, yes, around corners, not in a straight line.

I've just checked our workshop manual for a different vehicle, and to my surprisethe spider-gear end-play isn't given, and isn't adjustable, so I don't know how to help you there - I guess you could look at the wear pattern on the teeth and check that it is central.



Cheers

Greg Locock

 

[mrbreeze]

The wear pattern looks to be fairly even on all the spider gear teeth,I have about .018 clearance behind the spider gears (as near as I can tell due to they're shape it's hard to get a accurate reading) and the shaft has a little movement side to side but not more than a couple of thousandths. I get a slight whine around 40 mph and up. I have checked the ring and pinion setting,backlash and runout and they all look good and the bearings seem to be in good shape as well. Maybe I should just turn the radio up louder?
Thanks again for the help

 

[GregLocock]

Straight line or round corners? full throttle, trailing throttle or cruise? All speeds above 40 or just a range?

Diff whine usually is worse on cruise or trailing throttle, at some specific speed, rather than at all speeds. Could it be the gearbox? (try shifting into neutral). Have you stuffed around with anything else since the noise started?




Cheers

Greg Locock

 

[evelrod]

My money is on the ring and pinion as the culprit. Problem is, even with a correctly set up dif., once a noise has become noticible NO amount of adjustment will make it go away. The setup lash may be 0.003" to 0.015" (what I actually have seen) and not 'whine'. The whine most probably will not cause further mechanical problems (some difs whine no matter what is done to correct them) but it is a problem of perception. Customers just don't like to hear noises(my high frequency hearing is shot so I don't hear them anyway)!
Some causes---incorrect pinion spacer, wrong preload sleeve or wrong preload torque, incorrect lash setting, incorrect preload on carrier bearings, broken or chipped teeth, incorrect axel allignment(bent housing) in side gears, broken spyder gears, bad bearings, wrong lubricant and a lot more I can't think of right now.
Anyway, good luck. It is still one of the 'Black Arts'.


Rod

 

[mrbreeze]

Thanks for all the help everyone, I know the guy that owned the truck before me and he said it has always made noise from "Back there" he even had a local dealer replace all the bearings in the differential a few years ago. After checking all the usual things the only thing that looked out of place was the spider gear end play and I couldn't find any info about correct end play or what to do if it was to much, I think I will put it back in with new lube and do some more testing ( I never tied putting trans. in nuetral) and check tires & u-joints ect..it may be something I have to live with.
Thanks again