The Torsen Roar

[TheLion]

Well, the noise you hear/feel is very dependent on the transmission path into the cabin. Bushings are a big part of that; anything mounted on bushings as vibration dampers is done so for a reason. So, if you change that, you have to accept the trade off...

That's pretty much where I'm at. The modifier solved the excessively loud diff noise issue. Other than replacing the whole drive shaft with an after market solution with tighter bushings, I don't think there's much to be done. Either use the differential bushings and take the added performance or take them out and deal with degraded performance but a quieter ride.

For a street only car I'd say take them out, but I'm interested in auto cross and drag strip as well so I will probably just leave them in be satisfied. The car runs, delivers power and drives stellar other than some swaybars and tires it's pretty well rounded now.

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[wildcatgoal]

The noises the Torsen makes is transmitted through stiffer bushings (aka bushings with inserts in them) but is not caused by a bushing/bushing insert.

Yes I was being sarcastic. I didn't mean anything by it... apologies.

 

[MaverickGT]

However I'm not familiar with Torsen differentials and what's normal and not. Basically I can only describe as a roaring or binding noise (similar to a tire rubbing inside a wheel well, but more metallic) when taking sharp corners are low speeds under moderate throttle (which happens some what often).

It does not occur on larger more sweeping turns and lessens the harder I am on the throttle, obviously if I floor it in 2nd going around a corner the torsen does its job and both rear tires break loose and fishtail the car (where my standard EB base diff would just produce inside wheel spin).

Re-reading this. Now I know what that sound is. I hear the same sound on track which sounds something like a tire rubbing. Heard it again this weekend. It occurs on some fast turns and most slow sharp turns. The first time I heard it I thought my tires were rubbing but found no evidence of it. Seems like it has something to do with how the clutches manage torque differences between wheels. Not an expert at all. Maybe someone can chime in and explain it.

 

[Fast64ranchero]

Mine is very quiet, in fact smoother and quieter then the stock 3.55's with trac loc. I have craddle lockouts and vert. links.

 

[Agent_S550]

The Ford friction modifier is unbelievably good at what it does. It reminds me of whale jizz but it works. I've had quite a few rearends that fixed themselves just by pouring a bottle in. Glad to hear its better.

 

[wildcatgoal]

It reminds me of whale jizz but it works. I've had quite a few rearends that fixed themselves just by pouring a bottle in.

:lol:

 

[whatsup62]

The Ford friction modifier is unbelievably good at what it does. It reminds me of whale jizz but it works. I've had quite a few rearends that fixed themselves just by pouring a bottle in. Glad to hear its better.

You have a part # for that whale jizz?

 

[wildcatgoal]

https://smile.amazon.com/Ford-XL-3-...535946&sr=8-1&keywords=ford+friction+modifier

 

[EXP Jawa]

You have a part # for that whale jizz?

Once upon a time, friction modifers used, in part, oil derived from Sperm Whales. Not exactly the same as whale jizz, but not as fun to say... :lol:

 

[randotheking]

Not as far as my research as led. I found all kinds of GT500's, GT PP's etc. with the torsen and the "roaring / grinding / moan" noise complaints. Most of them were resolved by friction modifier. A few the modifier solved the issue temporarily.

I poured in the bottle last night and drive around. The diff is much quieter during the low speed sharp turns. You can still hear the "rubbing / roaring" sound, however it's very muted and far less noticeable than the drive train backlash / slop. As long as it stays this way I think this issue is generally solved.

I did notice however it take a bit more throttle to get the torsen to start biasing, it stay open diff under light very light throttle. That's basically what the modifier does is keep the worm gears from grabbing against the casing walls more so than just the base oil would. I'm guessing it modifies viscosity a bit to accomplish that. It's a trade off, but yes the torsen still locks under any significant throttle. It is a bit less linear however, it seems to suddenly start biasing as opposed to more of a linear progression so again it is a bit of a trade off but unless your in serious competition, for any hobbyist it still works very well and is immeasurably better than the fiction plate diff that was in there (basically useless under any power during turns).

Those sub-frame bushings really "locked" the rear end down and the car now feels like it's on rails as opposed to "floating" around a bit or the "rubber band" feeling some describe. The sub-frame bushings I would recommend for anyone as I don't think they really add the noise, at least according to Ford Performance. Most of the added noise is through the diff bushings which matter mostly for drag racing (I plan on doing both auto cross and occasional drag strip).

So I would call this a success.

My GTPP is a DD and I haven't noticed anything from the Torsen yet. 1,500 miles

 

[EricSMG]

Great thread. I'd like to touch on two points here.

The Torsen is actually a poor choice for sharp, slow turns, like turning onto a busy street. First, it does make a bit of a moaning sound and second, even worse, it lets the inside wheel spin a little too much - it always seems to be a half second behind my right foot. Sure, more throttle helps but that's not a solution because now you're the guy screeching and fishtailing. It seems to be an on/off device. A more traditional clutch LSD works dramatically better in these situations - it's smoother, quieter AND much more effective since zero inside wheel spin - a triple win. This is my first Torsen and for street use I'm really not a fan of it.

From this I'd say the FM is exactly what I don't want. I want more internal friction with less torque. If I end up relaxing the diff ratio to 3.55s (very likely) I will buy the loaded unit from Ford with the clutch LSD.

Bone stock PP with 600 miles on it, for the record.

 

[Jmart]

Sorry to raise up an old thread but this is the closest I can find to match my concern:
2017 GT PP here, 1500 miles on the clock. I've noticed that I get a very similar sound in reverse and at full lock when pulling out of my driveway in the morning. I always assumed this was the Torsen but figured I'd jump in and see if everyone else experiences the same.
Best way I can describe the noise: it sounds similar to a wheel rubbing on a fender but a bit more metallic, and it's clearly coming from the rear. I live in the Bay Area and this is early in the morning, so temps have been between 35-45 F when I've noticed it.

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