Talked with Pyle Brothers in Baytown regarding getting a 4.10 gear installed. Was very surprised to find out that use ordinary differential fluid when replacing the gear. I know the sysnthetic stuff that comes from the factory is extremely expensive and never has to be changed. They told me they have seen many vehicles (Ford,G.M.,Chrysler) that have had gears wear badly because of the synthetic and that's why they use the regular stuff. I am not particularly excited about having to change differential fluid every 15,000 miles from now on.

This place is the most respected rear-end shop in the Houston area, but do you buy their story? Are they just putting the regular stuff in so they can charge $100 less for the gear swap?

Alex

 

Alex: $100 difference for synthetics? I just did my rear end and had to buy 3 bottles to fill. The bottles were $8 a piece. Every single guy I know goes synthetic while they've got there diff drained.. never heard a single problem.

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1995 F-150 Regular Cab Flareside w/ 302 V8... Mods: Mass Air, K&N FIPK, Dual Exhaust (no mufflers), Lund Premier Tonneau Cover, Motorsports 9mm Plug Wires, full JL/Kicker/Pioneer system, Autometer 5" tach, Superchip, Precision Gear 3.73s

Best 1/8th ET: 10.6837 @ 64.9561 MPH

The F-150 Resource Guide

The F-150 Resource Guide-- a site dedicated to 1987 through 1996 F-series trucks.

 

I'd buy the oil myself and give it to them to put in, and be witness if you can.

 

There is a possible issue with break in. Several years ago the gear manufactures changed the method they use for hardning the gears, as per EPA rules. (so I've been told) This resulted in gears that require a break in period. To be safe use regular gear lube for the 15k miles, by then they'll be broke in (to say the least) and you can switch back to synthetic. Oh, the break in procedure I've gotten from Richmond gear calls for running the gears with the tires off the ground. Run it until the rear warms up. Then let it cool. Do this seveal times before operating under load.

 

Isn't there an additive you're suppose to use in addition to the lube for positraction rear ends?
noelvm

 

I just ordered a clutch re-build kit for my rear, this included a 4.oz bottle of friction modifier.. cost was around $70

Spiro-TEAM PSP

 

Tag on my rear axle reads

"75W140 Syn Only"

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Go Hard or Go home........
*Red 2000 SVT Lightning
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*PSP Chip
*Adopted 3/29/00
-98 Mustang GT Convertible 4.6L Supercharged with FRPP Eaton M112 @ 9psi, to many other handling/engine mods to list.....

 

When Ford did my 3.73's they insisted on the syn oil and ythe friction modifier. the modifier is supposed yto keep the noise down as well.

 

When I had my 3.73's installed the shop told me that the gears would be broken in at about 500 miles,they used regular fluid but said that after the break in to change it back to synthetic.

 

It might depend on whos gears you use? Had my 4:10 done by Pyle Brothers also, using USA Gears, not Ford. Would call them back if I were you and ask all the right questions first. As you said "the most respected rear-end-shop in Houston area", they do a lot of gears for a lot of racers.

 

Andre-

What kinda fluid did you get?

BTW...What were you running last night at HRP?

Alex