4.10 gear install prep questions

[ctrlraven]

So FINALLY after all this time I'm within days away from getting my 4.10 gears installed and show up Blackened300a lol

The questions I have are, I ordered a brand new Ford Racing diff since my factory spider gears were questionable, I know it's recommend that the clutch pak be soaked in fluid. Would it be smart to soak the diff in fluid before installed and what kind of fluid? (wasn't sure if it needed to be gear oil with or without friction modifier)

Also should I run dino gear oil (with or without friction modifier) for the first 500-2000 miles then change to full synthetic? If so what dino gear oil should I get?

Just trying to get everything lined up so there is no surprises on stuff I can control and hang up the install. My friend is being nice enough to bring an air compressor and tools to my work Friday or Saturday and knock it out for me.

Any other advice or tips would be nice, thanks!

[Glenn]

Interesting question on soaking the diff. Personally, I would not take a chance, I would soak the whole diff to insure the pacs are soaked. Soaking the pacs is critical to a good running posi. In fact, I soaked my pacs for two hours before installing. Use what Ford recommends and nothing else WITH friction modifier. Did you get the HD 8.8 Cobra Diff with the Kevar clutch pacs and HD F150 "S" spring. If not it will not hold up to over 400 HP.

Good Luck,

Glenn

[fastblackmerc]

Soak the discs in whatever you'll be running in the diff. No need to use different oil for break in. I used Redline 75w140, I think, from day 1 and have not had any issues.

[ctrlraven]

Interesting question on soaking the diff. Personally, I would not take a chance, I would soak the whole diff to insure the pacs are soaked. Soaking the pacs is critical to a good running posi. In fact, I soaked my pacs for two hours before installing. Use what Ford recommends and nothing else WITH friction modifier. Did you get the HD 8.8 Cobra Diff with the Kevar clutch pacs and HD F150 "S" spring. If not it will not hold up to over 400 HP.

Good Luck,

Glenn
I do have the Cobra clutch pak and HD "S" spring, those along with new spider gears will go into my factory diff which will be turning into a 31-spline unit as I plan on upgrading the axles to 31-spline down the road. I won't be near 400hp for a while so I'll be good to go. Yeah I think I will soak the whole diff for 2-3 hours pirior to install just to be on the safe side.


Soak the discs in whatever you'll be running in the diff. No need to use different oil for break in. I used Redline 75w140, I think, from day 1 and have not had any issues.
I'll either be running Mobil 1 or RP 75w-140 with a little shot of friction modifier to be on the safe side.

[Blackened300a]

So FINALLY after all this time I'm within days away from getting my 4.10 gears installed and show up Blackened300a lol

Finally!!!! Now the battle for a tenth of a second has begun!

I let my clutches soak in Royal purple gear oil for over an hour and then installed with the bigger "S" spring.
I been using Royal Purple gear oil without adding a additive for over a year and I haven't had any issues at all. Saturday Im pulling apart my rear as well to replace a leaky pinion seal and new axles with bearings.
Make sure you Loc-tite the ring bolts! My brother in law had his bolts back out and it was a disaster.
Good luck getting that bigger "S" spring in! Make sure a giant mallet is available and a lot of patience as well. :D

[babbage]

Soak the discs in whatever you'll be running in the diff. No need to use different oil for break in. I used Redline 75w140, I think, from day 1 and have not had any issues.


I disagree, and I'll say it again bad advice ^^^. Although you CAN break in your new gears using synth you shouldn't -- a fine metal powder is generated by the gears during the first 500 miles. (break-in) You'll want to DRAIN this fluid out after 500 miles!

Synthetics don't allow the gears to get hot enough and is too slippery for the metal. You want them to wear and get hot and mesh properly during break in. This is also the view of the experienced installer who did my gears. Break them in with dino oil - Ask a few shops and you'll find they agree.

My Suggestion is to use FM with regular 75w-90 gear oil for first easyish 500 miles - then drain and fill with AMSOIL 75w-110 (more power)
You can even get their neeto pump to use.

http://www.mercurymarauder.net/forums/attachment.php?attachmentid=17 778&d=1259108055

[Stranger in the Black Sedan]

If you use friction modifier (I needed it even with the Redline 75-140 synthetic) use the ford motorsports modifier. The CRC/Transx crap the auto parts stores carry did not stop the chatter but one bottle of the FMS did. Although I am just running dino 85-140 oil now, I change it often enough that the synthetic is a waste.

If you end up needing the gears installed I have done my MM gears and would be able to get yours done at my house in southern MD. I have the Rotunda/OTC pinion depth gauge kit and a shop press with a bearing splitter, those are really the only special tools you need (not sure what you'd need an air compressor for other than removing the pinion nut once and that can be done by hand)

Steve

[ctrlraven]

Everything inside the pumpkin will be all new parts and my friend is doing the install for free but I'm still going to give him some money. Going to do everything right in my heated shop.

[fastblackmerc]

I disagree, and I'll say it again bad advice ^^^. Although you CAN break in your new gears using synth you shouldn't -- a fine metal powder is generated by the gears during the first 500 miles. (break-in) You'll want to DRAIN this fluid out after 500 miles!

Synthetics don't allow the gears to get hot enough and is too slippery for the metal. You want them to wear and get hot and mesh properly during break in. This is also the view of the experienced installer who did my gears. Break them in with dino oil - Ask a few shops and you'll find they agree.

My Suggestion is to use FM with regular 75w-90 gear oil for first easyish 500 miles - then drain and fill with AMSOIL 75w-110 (more power)
You can even get their neeto pump to use.

http://www.mercurymarauder.net/forums/attachment.php?attachmentid=17 778&d=1259108055

I've had my gears in for over 50k, used Redline (no friction modifier added) and haven't had any problems. Drained the fluid and removed the cover after 25k and it was as clean as new, no metal particles at all. The one thing you DO NOT want to do is drive at a constant speed for the first 300 to 500 miles. You might want to install the bearing cap stud kit in place of the original bolts.

[GreekGod]

It is not necessary to soak the differential before installation. They don't do it at the factory, either. Just read the Ford shop manual! If you have it disassembled, you can soak the friction discs.

It is not necessary to change the lube after "break-in". It is not done with new cars, and they can go 200,000 miles without ever changing lube. New gears are already matched & lapped when they are made. There is no break-in period. Read your owners manual!

I was told Ford now recommends semi-synthetic gear lube. Adding Ford's friction modifier to the lubricant will avoid all chatter.

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[ImpalaSlayer]

i gave my gears about 2 miles of break in and said **** it. they still remain to be silent