How to tell when your clutch needs to be replaced.

Yep, thanks. I just need to know if the original was straight, then I could add in at least 1" in length, and screw the eyes in further, to get where I'm at now.

 

The linkage rods often get shortened to make the clutch work after the adjuster ring has been run in too far. I'm thinking this is the reason for the weld on your linkage rod. You need to get back to the original length of the rod. A salvage yard might be your best bet. A new one is likely special order and pricey. Once you have the correct length linkage and a proper clutch adjustment you'll have the truck back on track and eliminate all the mystery.

 

Thanks bender. I'll go visit another FLD tomorrow and measure the rod length and see if it's straight or bent. Easier to make one than wait and pay the $275 I was quoted.

The replacement clutch they tell me is a SP108391-81AM, but its only rated at 1400 ft-lb, whereas the engine rating 1450 ft-lb. The only way I've found to fix this is to change the flywheel from the existing 7" to an 8.5", and the clutch to SP108391-74 or 1650 ft-lb. Does this seem reasonable or is the 50 ft-lb difference between existing clutch and engine ignorable?

 

I had a feeling they'd have a whorehouse price on that piece new. Once you have the measurement you can bring your existing rod back in to spec or makeup a new one. International dealers sell the rod ends (heim joints) cheap.

Well, they did build it that way and assuming you haven't had recurring clutch failures in the past, I would probably run with it. If you pull a pup, run off road allot or plan on engine upgrades in the future the bigger clutch might be the wise choice.

 

Another job came up tomorrow so I lengthened the existing rod 1/4" with the play I could get from the eyes and put it back together. Adjusted the clutch with the ring and the release bearing now sits closer to the brake disc. It's still a hair over 9/16" but not 3/4 to 7/8 it was before. Figure if I add another 1/4 to the present linkage length I'll get the 1/2". The clutch grabs nice now, and there is a respectable amount of free play.

Don't know why the linkage was cut and modified to shorten it. The eyes could have been screwed in to do the same. In fact, the range of travel on the eye threads probably allows the linkage to be shortened 2" from max length.

That free play is so important, because without it, torque and cab movement relative to the frame can cause the clutch to slip and wear quickly.

Thank you for your help and advice Bender.

 

So far, three different places have told me three different types of clutches fit this truck. A 7", 8.5" and a 10" lol. Freightliner gave me an engine S/N from the VIN and said the flywheel is a 7". But the engine S/N on the valve cover is different lol. The flywheel of the valve cover label is listed as a 1062, whatever that means. Both engine S/N's also develop more torque than the 7" clutch can hold, so I'm wondering if the flywheel was changed to an 8.5". Another supplier looked up the Dana Spicer clutch number and said it's a 10". I'll have to do some more digging

 

It's great that you got it roadworthy and not missing a bunch of work while you're figuring it out.

When people don't follow the proper steps it gets confusing and sometimes they do anything to get it working including shortening linkage. There are probably more people adjusting clutches the wrong way than the proper way according to Eaton/Spicer. Most videos I've seen show the wrong way so it's no wonder people are taught and learn the improper methods.

Glad I can help!

 

Hopefully they changed it to the 10" and you can avoid the flywheel expense.

 

I'm having trouble with my transmission i am getting a cluck sound when I go to the last three high gears its a15speed eaton fuller i reasonly put new clutch input shaft main shaft 3 4 5 gears in the front box every time I go back up with it I get the same results is it something wrong is it the clutch not install correctly or maybe it could becoming from the rears could you please help me with this situation

 

If it was a clutch problem. You'd more then likely have the problem in all gears. Not just in reverse.

The clutch is going to do it's job and spin in the same rotation no matter what gear it's in.