Solid differential spacer results

[Softballer77]

Well, i've done WEEKS worth of research. Read a lot of people who were going to go with a solid spacer to hopefully cure the whine with their gears, but sadly I haven't found anyone or threads that have given the results afterward. Maybe they feel the problem is fixed so they just don't follow-up with anyone on the forums. Idk. Anyhoo...

In a week or two I'm going to install 3.90s with a solid spacer and shim kit from Ratech. Little history: I swapped my 3.31s for FRPP 4.10s and moser axles. One trip to the strip and they whine so bad, if the windows are up and the radio is off it's hard to even have a conversation. Plus, I have quite a bit of play in the drivetrain now back there, probably due to the backlash being out of limits from numerous launches. I'm already at redline going through the traps in 4th, so if I add more power, i'm going to need less gear, but didn't want to go 3.73s just yet. Like to be the guinnea on the 3.90s.

When I have this done, i'm going to install the rear brake kit from Billet Pro Shop so I can run 15s. So, there will be many birds killed in one job I'm hoping.

I will keep you all posted on how this all goes. AND, if ANYONE has had a positive OR negative result from using solid spacers over the crush, I'd love to hear. All I seem to hear are negatives on the crush, and nothing on the solid results.

Cheers.

 

[Beercules]

Solid is the way to go, just easier and no possibility of deforming under load. Don't know if ratech is like the yukon, but the yukon has no machining to fit right, just 2 spacer pieces with shims to go between for sizing.
I think a girdle would help the most. Forget if it's currie or strange who told me one of the reasons it whines after the track is because launches pull the gears apart and adds a second pattern. The ring gear/carrier gets pushed far enough out that it allows the bearings to spin in the caps (i need to post pictures). The girdle will help keep these caps where they belong. ( read some GM guys' posts somewhere where they thought everyone should have a girdle if you have power).

Another reason for whine I found while researching is because the bearings/races wear in and cause a little play for the ring gear (different backlash adjustments for new/old bearings). I'm thinking this is why people have quiet gears for a while, then they get noisy after some miles...even though they don't abuse the gears much. ( maybe install with a case spreader or second session for reshimming would help quiet everything down?)

As for the pinion spacer, I found out I spun the bearings and figured that's adding noise and it would be difficult to fix...upgraded to a 9" (the gears themselves will bend before they pull apart under load=no second pattern).

BTW, get strange axles...same price, and I bent my mosers without ever getting traction.

 

[Softballer77]

Solid is the way to go, just easier and no possibility of deforming under load. Don't know if ratech is like the yukon, but the yukon has no machining to fit right, just 2 spacer pieces with shims to go between for sizing.
I think a girdle would help the most. Forget if it's currie or strange who told me one of the reasons it whines after the track is because launches pull the gears apart and adds a second pattern. The ring gear/carrier gets pushed far enough out that it allows the bearings to spin in the caps (i need to post pictures). The girdle will help keep these caps where they belong. ( read some GM guys' posts somewhere where they thought everyone should have a girdle if you have power).

Another reason for whine I found while researching is because the bearings/races wear in and cause a little play for the ring gear (different backlash adjustments for new/old bearings). I'm thinking this is why people have quiet gears for a while, then they get noisy after some miles...even though they don't abuse the gears much. ( maybe install with a case spreader or second session for reshimming would help quiet everything down?)

As for the pinion spacer, I found out I spun the bearings and figured that's adding noise and it would be difficult to fix...upgraded to a 9" (the gears themselves will bend before they pull apart under load=no second pattern).

BTW, get strange axles...same price, and I bent my mosers without ever getting traction.

Thanks for the indepth reply.

My experience is that my stock ones even after many many launches, never whined a bit. Now, I have heard of other's having their stock ones whine just slightly. Just sucks how just swapping the ring and pinion once, and you have such a loud whine.

Yeah I'm not going to swap to Strange axles and ditch my Mosers at this point. So far they are holding up fine, and I'm sure still much better than stock. All I'm looking for.

I have run into a lot of myths debunked with gears over time. For ex:

"FRPP are better and don't whine over other gears "(Richmond, Motive, et). Well, My FRPPs sing like crazy, and the Motives I had in my older mustang were quiet as could be with tons of 1st gear nitrous'd launches on them. Not to mention, didn't Motive provide gears to Ford for a bit of time anyways?

"You have to heat cycle your gears and change out the fluid shortly after install". How many people have heat cycled their gears and swapped the fluid 500 miles after buying their brand new car? Pretty much zero. It's not needed. You can, and i'm sure breaking in something new that is metal on metal is a "good idea" to change fluids kinda quickly to rid any floaties in there, but it's not required. And to add, my Motives in my last Mustang were doing 2nd gear 100 yard long black marks on the first day 20 miles after install. Still no issues.

In the end, you can spend an ungodly amount of money on setting up a proper rear end. It shouldn't be needed. I just want quietness as I had when it was before the gear swap. My goal is to not only continue to run 10s or faster, but be able to comfortably drive this car from Cali to NY. I don't want it to be, nor plan on it to be a drag only, too uncomfortable to drive daily vehicle due to the domino effect of every upgrade creating a negative side effect.

 

[railroad]

I think you can get into a solid spacer and girdled cover without breaking the bank. Probably the best and cheapest mods without going to a 9". After market suspension will transmit some noise you would not normally hear with factory stuff. Still, set up right, cruising should be quiet. I put 3.73 Ford gears in mine. I have not been on the strip, but have made some hard pulls. Still no whine. I did the heat cycling, but have not changed lube. I used all the stock bearings except the big pinion bearing. It got tweaked on removal.

 

[Softballer77]

If you dont want it to whine, Id refrain from the strip then. 1.5 60s and it was immediately down hill for me.

Maybe I'll look into a girdled cover. Thanks.

 

[Njtony]

Has anyone gone back and had specs measured to see what is happening with the gears to make them whine. For now I went ghetto and stuffed my trunk with carpet padding which reduced the whine inside the car.

 

[railroad]

The easiest thing to check is the pinion preload. The pinion flange should not move front to rear. You can check this with the driveshaft in. If it does move, drop the drive shaft and tighten the pinion nut enough to get all the slack out. This might get the whine out, but be aware the crush sleeve did collapse enough to create the slack you felt. If there is no slack in the pinion, the carrier has moved and bearing possibly lost preload.

 

[NIXDSG]

So I did the whole thing this year:
- welded the tubes to center section
- 9" ends
- Moser axles
- traction lock (removed torsen)
- welded the BMR lower relocation brackets
- BMR adjustable LCA
- BMR upper bracket and adjustable upper
- 3.73 gears
- '12 caliper brackets
- 15x10 WELD RTS
- set backlash at .008"
- pinion preload perfect in the middle of the spec range
The first 400 miles were street driving with DR tires. All good, no whine. Was kind boring as it tracked extremely straight (a little boring, actually).
Bolted on the 15x10's with MT ET Street Radial and headed to the track. First time ever with good tires so still learning. I did my first 1.80 60', I know slow but first time with good tires and doing a "launch". The next day I had gear whine. So...

Took the rear apart, backlash opened up to .014". Pattern was perfect.
Ordered up a Yukon solid pinion spacer, installed and set backlash back to .008. Noisy! Took it apart and inspected bearings closer. Carrier bearing races had a little frosting on the cups. The large pinion looked bad, had "sparkles" all over the cup. Not pitting, just little spots all over the running surface. The rollers had lines around, you could just feel them with your finger nail. So, all new bearings, seal, and pinion nut ($350). Install with .009" backlash. Still whines.

Checked pinion angle, 50 times to make sure. -1.0 degrees.
Remove BMR LRA and replace the rubber stockers. Still whiny noisy sum bich.

So, tomorrow I'm going to drive it. I will turn up the radio. Consider an OR H pipe
Investigating a 9".

NIXDSG

 

[railroad]

I did not understand where you got the increase in back lash, pinion moving or carrier bearing wearing. Either way something moved. My thoughts are once you run the gears while whining, there is a good chance you will not get it out. I have had 9" gears that whined in 2 different chunks. I have never changed the lube after heat cycling, but with the report on the bearings breaking down, it very well might be good advise.

 

[Snoopy49]

NIXDSG,
How did you set the preload on the carrier bearings?

 

[NIXDSG]

SNOOPY,
I'll get the details on how he set that up. I know it was buy the book, I remember it being snug. The guy that set this up has done a few, he has done gears for a living for many years (not just automotive).

Railroad,
agreed, I don't get it. I also don't understand the rear pinion bearing condition, we cleaned and cleaned before assembly. The only regret is that we didn't reinstall the alignment bar into the housing to confirm that it was still straight. Not saying that my lame 1.8 would bend a housing, but it was apart and would have been easy to check.

NIXDSG

 

[Catmonkey]

NIXDSG,
How did you set the preload on the carrier bearings?

You add shims to the shim pack. You want an additional .006" of shim on each side from zero preload.

 

[NIXDSG]

Catmonkey, that sounds right. I'll confirm with him.

NIXDSG

 

[railroad]

Catmonkey,
Good point, especially on new bearings. I usually just maintain the total shim thickness with the original bearings. Makes me wonder if the factory preload is enough. The carrier has to be driven in, so it definitely is not loose.

 

[Snoopy49]

According to the factory manual, there are no shim packs, just different size one piece shims, that are hammered into position with a special installation tool. No way are you going to be able to install a .006" shim using the factory method. A spreader would be the only option and I don't know if the axle housing is setup for a spreader.
The $18.79 price of each shim would make it very costly for an individual or small shop to have a large enough assortment of shims to accomplish the job. This may be why so many people are having a problem with noise after a gear swap. The differential bearing preload is not being set correctly.

Here is the factory procedure.

View attachment Differential Ring And Pinion.pdf

Here is a spreader used on a Dana 60 housing, the thing is huge and heavy.

 

[Catmonkey]

Ford does use a solid cast iron shim on each side, but Ford Racing and other vendors make various size shims that can be used with a thinner cast iron shim. Having a large assortment of the factory cast iron shims to enable you to set up a differential would get awful expensive.

 

[Snoopy49]

How would you install a thin shim without destroying it or deforming it without a spreader? Remember that there is suppose to be no clearance between the shim and the case or bearing, before you add the .006" shim on each side of the differential housing.

Here is a list of the shims.

View attachment Differential Shim Size Chart 4067.pdf

 

[Softballer77]

So I did the whole thing this year:
- welded the tubes to center section
- 9" ends
- Moser axles
- traction lock (removed torsen)
- welded the BMR lower relocation brackets
- BMR adjustable LCA
- BMR upper bracket and adjustable upper
- 3.73 gears
- '12 caliper brackets
- 15x10 WELD RTS
- set backlash at .008"
- pinion preload perfect in the middle of the spec range
The first 400 miles were street driving with DR tires. All good, no whine. Was kind boring as it tracked extremely straight (a little boring, actually).
Bolted on the 15x10's with MT ET Street Radial and headed to the track. First time ever with good tires so still learning. I did my first 1.80 60', I know slow but first time with good tires and doing a "launch". The next day I had gear whine. So...

Took the rear apart, backlash opened up to .014". Pattern was perfect.
Ordered up a Yukon solid pinion spacer, installed and set backlash back to .008. Noisy! Took it apart and inspected bearings closer. Carrier bearing races had a little frosting on the cups. The large pinion looked bad, had "sparkles" all over the cup. Not pitting, just little spots all over the running surface. The rollers had lines around, you could just feel them with your finger nail. So, all new bearings, seal, and pinion nut ($350). Install with .009" backlash. Still whines.

Checked pinion angle, 50 times to make sure. -1.0 degrees.
Remove BMR LRA and replace the rubber stockers. Still whiny noisy sum bich.

So, tomorrow I'm going to drive it. I will turn up the radio. Consider an OR H pipe
Investigating a 9".

NIXDSG

Wow NISDSG...thanks for the awesome write-up. Sorry it didn't work out for you. Kinda gives me false hope, but I'm going to press on.

 

[BMR Tech]

Remove BMR LRA and replace the rubber stockers. Still whiny noisy sum bich.

Not to threadjack, but I really enjoyed reading this. lol (people get mad at me when I tell them that the gear whine they got after the trip to the track is NOT our LCA)

 

[Catmonkey]

How would you install a thin shim without destroying it or deforming it without a spreader? Remember that there is suppose to be no clearance between the shim and the case or bearing, before you add the .006" shim on each side of the differential housing.

You might substitute a .025" shim for a .018". It won't be exact science, but if you end up with an additional .012" for the preload, you won't change the backlash that much if you add .005" on one side and .007" on the other. You would need to drive the cast iron shim next to the thickest shim you have in your stack, not the thinnest. You could also determine the total shim size using the smaller shims and order the correct cast iron shim, if you want to wait a few more days to put your car back together.

Anytime you're going to change the gears or the differential, the original shims are not likely to get you within specs, so you need enough shims to make minor adjustments in both directions to get the proper drive and coast patterns. This is pretty precise work and some special measurement tools are needed to do this right. You may find yourself needing to press the pinion bearing on and off a few times to get the correct shims between the bearing and the pinion gear to get the right pattern on a new gear set. With a new differential and the original gears, you will need to get the backlash close to what it was before you took it apart with the preload setting. Your OEM shims are not likely to get it right either. When I installed a trutrac I needed an additional .015" of shims to get the right pre-load using the OEM gears.