• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

Is everybody here using Friction Modifier??

  • Thread starter Thread starter SmockDoiley
  • Start date Start date Feb 20, 2004
  • 1
  • 2
Next
1 of 2 Next Last
S

SmockDoiley

New Member
Jun 14, 2003
1,591
2
0
San Diego, CA
Feb 20, 2004
#1
  • Feb 20, 2004
  • #1
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.
 
B

bapford

New Member
Jan 17, 2004
40
0
0
Feb 20, 2004
#2
  • Feb 20, 2004
  • #2
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

Founding Member
Sep 9, 2000
4,675
38
119
Antelope Valley, SoCal
Feb 20, 2004
#3
  • Feb 20, 2004
  • #3
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

Member
Mar 16, 2003
273
0
16
Sunny Florida
Feb 20, 2004
#4
  • Feb 20, 2004
  • #4
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
 
L

L8 MUSL

Active Member
Jan 20, 2003
1,664
0
36
Carlsbad, Ca.
Feb 21, 2004
#5
  • Feb 21, 2004
  • #5
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

New Member
Jan 9, 2004
218
1
0
Opelika/Auburn, AL
Feb 21, 2004
#6
  • Feb 21, 2004
  • #6
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!
 
S

SmockDoiley

New Member
Jun 14, 2003
1,591
2
0
San Diego, CA
Feb 21, 2004
#7
  • Feb 21, 2004
  • #7
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

Mustang Master
Apr 10, 2002
9,039
6
79
Charlotte, NC
Feb 21, 2004
#8
  • Feb 21, 2004
  • #8
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?
 
S

sleeper89

New Member
Nov 18, 2002
388
0
0
Toronto, Ontario
Feb 21, 2004
#9
  • Feb 21, 2004
  • #9
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

Mustang Master
Apr 10, 2002
9,039
6
79
Charlotte, NC
Feb 21, 2004
#10
  • Feb 21, 2004
  • #10
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.
 
L

L8 MUSL

Active Member
Jan 20, 2003
1,664
0
36
Carlsbad, Ca.
Feb 21, 2004
#11
  • Feb 21, 2004
  • #11
SmockDoiley said:
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.
Click to expand...

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
 
1

1hot5.0

Founding Member
Sep 6, 2002
1,615
0
0
Surprise, Arizona
Feb 21, 2004
#12
  • Feb 21, 2004
  • #12
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

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,269
17,957
224
Massachusetts
Feb 21, 2004
#13
  • Feb 21, 2004
  • #13
Yup....i use the stuff.

Real nasty smelly stuff too
 

83 Capri 5.0

New Member
Dec 3, 2002
92
0
0
Vancouver, Canada
Feb 21, 2004
#14
  • Feb 21, 2004
  • #14
Got an Auburn Locker - no modifier required. I double check this with reputable rearend shop here in Vancouver.
 

cardudeusa

Founding Member
Oct 22, 2002
1,744
5
48
Home of the Florida Gators!
Feb 21, 2004
#15
  • Feb 21, 2004
  • #15
I used a synthetic gear oil, and no friction modifer. Been that way for about 20k miles.
 

maverick0716

Founding Member
Jan 12, 2002
3,924
0
56
Chilliwack, BC, Canada
Feb 21, 2004
#16
  • Feb 21, 2004
  • #16
cardudeusa said:
I used a synthetic gear oil, and no friction modifer. Been that way for about 20k miles.
Click to expand...

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

IndyBlk5.0

New Member
Nov 24, 2003
1,122
1
0
New Whiteland, IN
Feb 21, 2004
#17
  • Feb 21, 2004
  • #17
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

Founding Member
Oct 22, 2002
1,744
5
48
Home of the Florida Gators!
Feb 21, 2004
#18
  • Feb 21, 2004
  • #18
Oh, ok. Knew I used synthetic for a reason.
 

Michael Yount

Mustang Master
Apr 10, 2002
9,039
6
79
Charlotte, NC
Feb 21, 2004
#19
  • Feb 21, 2004
  • #19
If the Auburn's a locker no modifier is needed - it's only needed for clutch-type limited slip units.
 
S

SmockDoiley

New Member
Jun 14, 2003
1,591
2
0
San Diego, CA
Feb 21, 2004
#20
  • Feb 21, 2004
  • #20
"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.
 
  • 1
  • 2
Next
1 of 2 Next Last
You must log in or register to reply here.

Similar threads

My stinky friction modifier story
  • nicholase
  • Jan 4, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
10
Views
846
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jan 6, 2025
BlakeusMaximus
B
Where to go from here on my build…
  • B0udreaux
  • Jul 14, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
8
Views
240
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jul 18, 2026
AeroCoupe
3
Eight inches is enough for me...
  • 351MooseStang
  • Nov 27, 2025
  • 1974 - 1978 Mustang II Talk & Tech
Replies
5
Views
614
1974 - 1978 Mustang II Talk & Tech Mar 2, 2026
Bullitt347
What's your tow rig?
  • LILCBRA
  • May 31, 2026
  • Other Auto Tech
Replies
3
Views
184
Other Auto Tech May 31, 2026
LILCBRA
1
Engine Motor swap from a 2003 Explorer
  • 1996mustang new
  • Oct 9, 2025
  • SN95 4.6L Mustang Tech
Replies
7
Views
635
SN95 4.6L Mustang Tech Oct 16, 2025
squeak93
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?