I took my 04/04 4x4 Crew in to the shop yesterday to have the limited slip checked out. I noticed on the wet streets that only one tire would spin whenever I pulled onto the highway. Every limited slip I've owned in the past would fishtail. Anyway, the service advisor had the mechanic check it out and they tell me it meets the minimum torque spec.

Does anyone here know what the torque spec is? The service advisor couldn't tell me. How is the torque checked? Thanks.

 

The test can be done 2 ways.

1)the entire carrier is removed from the diff and placed in a fixture with a special holder an a special tool in inserted into the side gears axle spline.
A torgue wrench is applied to the tool and a minimum of 20ft/lbs to get the clutch packs to slip.

Shims are required behind the clutch packs to adjust the slippage within spec.

2)the way I've seen it done is with the carrier still in the truck. with the wheels removed an rear brake calipers removed .a special tool fitting the axle bolt pattern is bolted to the axle and a torque wrench applied getting the same results, but is not as invasive surgery so to speak as above.

Rich

 

What my service guy did was jack one tire off the ground and put a 120 ft-lb torque wrench on a lugnut. If the torque wrench clicked, it is in spec. If the tire spins, it is out of spec. Needless to say I'm in disbelief that Ford recommends this method.

 

really wow that amazing what will they think of next ????

 

I've read that adding a small bottle of Chrysler/Dodge modifier really helps.

 

ssls6 I had problems with my limited slip as well ,There was alot of good info on my post (limited slip or not by rescue emt)i can only tell you some things that i didn't mention on my reply. when i went to the dealer with the same problem your having they told me at first i didn't understand the limited slip thery . I told them the info. i got from my post (torque test ,friction modifier,ect. when they reallized i did my home work it was a different story. saying they would do a torque test. At firt they made shure that both wheels turned the same way when off the ground (non limited slip will turn opposite directions ) it passed . next they put one wheel down with a rolling jack under it . it never moved yup, they said there is somthing wrong ok. Know they had to narrow it down placing a torque wrench on what looked like a wheel allignment gig did a torque test witch told them that the clutches must be set up wrong ,to much friction modifer , or the pinion ring was not shimed right the dealer orderd a pinion and a clutch pack for my rear end . it has not been installed yet i will post the results of this on my post please post a reply on my limited slip post so we can keep tract of this issue. The answer to your question what the dealer said was a torque of 200 foot pounds on the brake away wheel they are going to replace the oil in it so a oil test for modifer will not be done good luck rescue emt.

 

Thanks for the response. 200 ft-lbs feels like a better number than the 120 ft-lbs I was told.

Regards,
Richard

 

just to get back to you on my truck i took it in yesterday to have the parts replaced. the dealer told me that the oil they took out was not the right viscosity and my clutch pack was bad (only 6000 miles)? so i would be persuing the matter if i was you. the dealer also put the latest flash in I took my truck out power braked it and guess what two nice posi marks on the road and it runs stronger with the new flash in the computer i'm hhhhappy