Is everybody here using Friction Modifier??

[SmockDoiley]

So I've never heard the magazines or anyone in here talk about Posi additive(friction modifier). Yet it is essential to use in any rearend with posi. I picked up my rearend from the shop and they told me to add gear oil of course and posi additive. I headed down to the dealership and they set me up with a small bottle for 4 bucks, and said I have to use it since I have a posi. I'm just making sure everybody here is doing the same because nobody ever mentions it when they are talking about rebuilding their trak-loc, or installing gears.

 

[bapford]

Yep need to do that to reduce or eliminate the chatter associated with the rear-end clutch. Don't blow it off, unless your running a full spool race rearend, which I doubt if you're on the street.
BP

 

[65ShelbyClone]

Yep, you gotta use it. You wont get proper T-Lok function if you you dont. You must not read Mustang and Fast Ford very often (its a classic Mustang rag anyway) when they do yet another Currie rear end install. They always mention the friction modifyer.

 

[302efi]

I never used it when I rebuit my rearend 10k ago ...just straight 80-90w ... I've had no problems with chatter or ANY one leg burnouts. I asked this same question a while back and I got mixed answers on the subject, so I figured what the hell, I'll go for it. I'm very happy with the results. I will tell you one thing, the rear locks up harder off the line

 

[L8 MUSL]

That was one of the few things I didn't do myself.
I see you are in S.D., call Jerry at Oceanside driveline. He has been building rear ends for 40 years he has some good tricks for setting up the 8.8 traclok. He did mine and it works awesome. If you're going to do it yourself, give him a call and pick his brain.

 

[banditmwp]

I used friction modifier, but not the ford stuff...i got some from our local BG rep called LS2. So far so, good...and it was free too!

 

[SmockDoiley]

I know its needed. I just wanted to make sure everybody knows it is and apparently a lot of people dont use it. As for rebuilding a Trac-lok, thats out of the question. I'm running an Auburn Pro, and 31 spline axles. I'm making way too much power for a TL. I read those mags all the time but I never see a mention of the stuff.

 

[Michael Yount]

smockdoiley - (forgive my ignorance) if the Auburn diff is a clutch-type limited slip differential unit, then you should use the friction modifier for smoother, quieter street operation. If it's a locker (mechanical, electrical or pneumatic) or a torque-sensing type of differential, then you don't need the friction modifier. So educate me - what type of diff is the Auburn unit?

 

[sleeper89]

if i remember correctly the auburn in a cone-type torque sensing unit. no clutches so once it wears out it's done.

-steve

 

[Michael Yount]

Steve - I guess we'll see if smockD knows what he's got. Actually, it's the clutches/springs that usually do the 'wearing out'; the beauty of the torque sensing units is that there's nothing to wear out - however, like anything mechanical, they can be broken.

 

[L8 MUSL]

As for rebuilding a Trac-lok, thats out of the question. I'm running an Auburn Pro, and 31 spline axles. I'm making way too much power for a TL.

You didn't mention that.
My TL has held up pretty well but I'm just under 400 rwhp.
It was set up without the S spring and with extra discs so that it locks up more positive and still has no chatter.
Again, give Jerry a call (I don't mean to ask "if" but maybe how much modifier to use with the Auburn) the guy is a drive line guru and a real nice guy.
But, maybe you are an expert and if so, I don't mean to offend

 

[1hot5.0]

I was told I had to use it. My traction lok clutches were too tight after install, and there was a grinding sound. The installer said that the friction modifier couldn't get in between the clutches, and he had to take out a couple clutches.

Now that the friction modifier has hit all the clutches, there is no rear end chatter and I get nice 2 legger burn outs.

 

[Mustang5L5]

Yup....i use the stuff.

Real nasty smelly stuff too

 

[83 Capri 5.0]

Got an Auburn Locker - no modifier required. I double check this with reputable rearend shop here in Vancouver.

 

[cardudeusa]

I used a synthetic gear oil, and no friction modifer. Been that way for about 20k miles.

 

[maverick0716]

I used a synthetic gear oil, and no friction modifer. Been that way for about 20k miles.

Usually the synthetic gear oils already have the friction modifier in them.

 

[IndyBlk5.0]

isnt 75w80 the correct weight of synthetic gear oil to put in the "pumpkin" And do i need to put a 4oz bottle of friction modifier in too?

 

[cardudeusa]

Oh, ok. Knew I used synthetic for a reason.

 

[Michael Yount]

If the Auburn's a locker no modifier is needed - it's only needed for clutch-type limited slip units.

 

[SmockDoiley]

"Have you ever tried to take off from a standing start, only to have one tire go up in smoke? When you need maximum traction, you need traction from both rear wheels. And there's no better way than with this Auburn Pro series limited slip differential from Ford Racing. It features cone-type clutches with approximately 50 percent more torque bias for excellent performance and durability on the street--without breaking the bank."
Thats the direct quote from Summit Racing. I know it uses a conical design but its talking about the clutches so it does have clutches. The shop that built the rearend and the Ford dealer both said it needed the stuff. As for weight, the dealer suggested Ford's synthetic 75w-140, but they wanted $11 a quart. I had just gone to a chevy dealer and paid $48 for synchromesh so I turned down Ford. I ended up getting pennzoil but all they had at the store was 80w-140. I said close enough and called it good.