I was told I needed the posi clutch packs replaced in my 2000 F150. I was quoted $900 from the dealer. Has anyone else had this performed? If so, what was the cost?

 

I just had the clutch packs replaced on a Trac-Lock (limited slip) diff. I got a price of 590 from the dealership.

 

You can get a variety of estimates, but I agree with Wittom. That price is substantially high. That price is close to a NEW differential AND gear set installation.

 

Why do they need replacing? If it is because the clutches are chattering going around corners, just add another bottle of friction modifier.

I had chatter in my 2000 trac lok rear. I changed the fluid and added a bottle of modifier and it didn't help. Then I found out I had a leaking axle seal, so I drained it again. This time I put two bottles of friction modifier in and it fixed it. The parts guy at the dealer suggested it. I don't know if it has a deleterious effect on the film strength or lubricating properties of the 75w140 synthetic grease.

There is a TSB on this subject that says the fix is to change the clutch pack and reduce the clutch pack shims by 0.010".

Someone else posted that Walmart is selling 75w140 synthetic now and I saw some tonight in Walmart (store brand). It cost over $8/bottle which compares to the dealer charge of $13 to $15 / bottle.

 

I just had mine replaced last week at the dealer and it cost me just under $800 (before they deducted the $117 service they did the week before and it did not fix the problem). Clutch packs replaced - problem solved.

 

Those prices sound high. You can buy the whole tractionlock unit for an 8.8 for just over $200. Labor shouldn't be over 3 hrs.

 

What is the reason for adding the modifier prior to the fluid? Does it not mix correctly, if fluid added first, then modifier?

I noticed all modifiers say to add it prior to adding fluid. I wonder if this might be part of my problem. The dealer serviced my diff a few months ago, but did not add modifier. I went back, and added 7 oz. of the Trans X modifier. It has same OEM spec #as the Ford FM. No difference in rear end problems, when making a turn. also, have a loss of power and mileage since the fluid change. 75W140 was used by the dealer.

Thanks, R1968

 

I would think that you should add the modifier first just to make sure that you get a whole bottle of it in the diff. before you fill it with the 75w140 so that you don't exceed the required level. So in the case of a complete Diff. fluid change, add modifier first, then top off with proper fluid up to indicated level.

If it was to add modifier only, check fluid level first, remove some if necessary, add bottle of modifier, then top off with fluid.

??am I making any sense here

 

I probably could have gotten it done cheaper, but I do not know that much about differentials and if I took it to a shop that I had never been to before, they could have screwed me for more. Plus my dealer gave me a loaner for the three days that they had my truck and an independent place would not have done that.

 

I just added another bottle of friction modifier to my '97 when it started chattering. That was about two years ago and it's still running alright.

If it's a 9.75" rear, you'll make up new words replacing the clutch packs yourself. The guy at the dealer will probably make up new words replacing the clutch packs. I'd add a bottle of friction modifier to it before anything else.

 

For about $650 or less you can get a brand new Auburn limited slip differential installed. It is a far superior limited slip differential, more aggressive, and more durable than the Trac-Lock. I agree with max mitchell don't put in new clutch packs.

 

I added a second bottle of modifier, about 10 days ago, and now the rear end noise is getting worse. It is going to the shop in the morning. My only fear, is they say it is ok. I need to travel about 9 hours from home in a few weeks. I do not need it breaking down on me.