so far so good

[rockyracoon]

well I just took a 20 min test drive after installing 410s,and the early results are promising.I thought I noticed a faint whine on decel from around 40 mph on down to say 25 mph,but im not sure if that is tire/road noise or not, it may have been there with the old rear gears and I just never took notice to it. when I pulled into the driveway I reached under and felt the diff cover,expecting it to be red hot,and to be honest it really wasnt very hot.

one thing however is the fact that I did not add additional shims to preload the carrier bearings after I dialed in my backlash,hopefully the backlash doesnt open up much, it was around .009.

I dont know if I would have wanted to tear it all apart again,if there would have been some noticeable whine.I was thinking I would bite the bullet and take it in somewhere.to me that is a really rough job,extremely time consuming with having to do mock ups and such,especially when you are in a 1 car garage,and IMHO even interpreting gear pattern is tough unless you are gonna reinstall the axles,calipers,rotors,so you can put a load on by applying the emer brakes,I was using a rag wrapped around a breaker bar wedged between the ring gear.

BTW there is a redesigned crush sleeve,which supposedly only takes about half of the torque to get into the proper pinion bearing preload spec.

 

[fast97gt]

.009 is pretty good, considering the use of new bearings. .014 is nominal for old bearings. but a slight whine on decel is ok if only minimal. ive got a brand new 3500express van and it has a whine on decel and it brand new. mine is just now having an almost unnoticible whine after 50k or so hard miles, but mine more than likely ready for a complete overhaul, (new bearins and trock-lok referbish) the gears are fine due to me narowing it to the outer pinion bearing from the pinion losing it preload from slamming gears over the last 4.5years.

 

[mrvax]

I always thought a slight whine on decel was normal with the lower gears.

 

[rockyracoon]

Ok so I got home from work around 8PM and proceeded to open her back up.

I just now pulled the carrier back out,and tomorrow I will re shim the pinion.I hope that the 60 miles or so that I put on the gears hasnt caused a permament wear pattern.

 

[wmburns]

My 1st rebuild had mixed results. On the 2nd one, I decided to remove the entire axle assembly and work off of axle stands. IMO, the extra effort required to remove the axle was worth it. It was SO much easier to measure pre-load and to torque the pinion nut. It was nice to measure back-lash and check the paint pattern while setting in a chair instead of on my back.

So why do are you re-shimming the pinion? That's like doing the entrie job again.

.009 backlash is within the spec although on the low side (esp for an automatic).

Just wondering, how did you set the pinion pre-load?


>>>
Ring gear backlash 0.203 mm - 0.381 mm
(0.305 mm - 0.381 mm preferred)
0.008 in - 0.015 in
(0.012 in - 0.015 in preferred)

 

[rockyracoon]

well basically im re doing it because of the whine.it was faint on decel between 30 and 40 mph.however it was also prevalent at roughly 2 times that speed from like 80 on down to 60,which I didnt know until I took the car on the highway.

as far as setting up the pinion shim I just went by the pattern,which wasnt the easiest to read,I really need to find a way to put a load on the setup to aid in interpreting.

in terms of the pinion preload,I used an inch lb torque wrench set to around 20"lbs.

 

[wmburns]

To get a good paint pattern, try this trick. Use a closed end wrench on the ring gear bolts. Use the wrench to turn the ring gear. By driving the ring gear into the pinion, the paint transfer should make a readable pattern.

 

[rockyracoon]

mr burns I tried rotating the carrier by a ring gear bolt,but pattern tests are still hard to interpret,so since the original shim was .037,and I already tried a .035,and the car was whining on decel im assuming the pinion is too close,so I went with an.030 and it still whines on decel between 40and 30 MPH but not anywhere else previously it was whining at 40 and 30 and also at 80 and 60.

does any one put any faith in the MHD method ? which is measuring the thickness of both heads and subtracting numbers from 4.415 and subtracting the difference from each other,when I did that it was telling me to go with a.016 shim,but when I ran a pattern it was way out by the top of the teeth.

the whine isnt very bad at all so this time I may live with it. I mean it takes like 8 hours from setting the car up on stands,to taking it off of the stands,oiled up and ready to go.

 

[wmburns]

I am confused. If the pattern is towards the end of the ring gear teeth (outer/inner Circumference), isn't that adjusted with carrier shims? The pinion shim moves the pattern up/down along the long axis of the ring gear.

Because the pinion shim is so hard to change, the first set up involves measurements to center the pinion within the ring gear. Then the carrier shims are adjusted to dial in the backlash and fine tune the pattern.

I would have thought that the paint pattern would have been the ultimate gold standard test. What are you using for paint? Pictures?

 

[rockyracoon]

when I originally set it up with the .016 pinion shim the pattern seemed a little bit more pronounced maybe because the R&P were both completely clean ( no gear oil residue,anyway that pattern showed as being on top of the teeth(opposite the root)then when I decided to get it in closer to the root I went with a 0.35 which was much closer to the factory(.037) the pattern was still readable,and it looked kinda centered from root to top,im not talking heel to toe,at that time the backlash was .009,so I went with it,and thats when I had the whine on decel.now on my latest round I went with a .030 ,and still had the whine on decel that recent setup was with a .010 backlash.the pattern has always been somewhat off from heel to toe,coast side towards the heel and drive side being towards the toe,which I have gathered is acceptable providing the pattern is centered.

Im still up in the air as to wether im gonna try again or just go with what I have,since as stated the whine isnt all that bad.between both setups I probably have less that 125 miles,but from what I have heard there comes a point in miles traveled when the whine is permamently inherent in the gear.

in my area a ford dealer would probably charge in excess of $500.00 to setup a set of gears,and thats the only place I would take it to,however im not leaning towards that.

at some point soon I will open it back up to recheck the backlash,and also try and sneak a.005 increase on both sides,but without a case spreader it may be kinda tough.im going to get some more carrier shims to have on hand in case I need them.

im using the marking compound that came with the master install kit.