Hey guys, I did some searching but couldn't seem to find anything on the current symptoms I'm having. It's an 85 F150 2WD with a 300 I6 and 4spd trans.

Basically, the past couple weeks I've noticed a strange hot/burning smell whenever I get out of my truck after driving it. It's not overheating and it's certainly not a coolant smell, but kind of smells like burning grease? I'm wondering if it's the clutch/trans because it has also developed a "ticking" noise when it's sitting in neutral with the clutch out...if I push the clutch in the ticking goes away. I also have a grinding sound (almost like gravel rolling around) in 4th if I start accelerating or pulling up a hill. I've never had a clutch go out on me before, so I'm honestly not sure what burning clutch smells like.

I also get a whiff of what smells like exhaust inside the cab when I come to a stop after driving down the highway for a few miles, but it isn't exactly the same hot smell I get outside the truck once I've arrived (I think).

Any ideas? Thanks for all the knowledge you guys are so willing to share...you got me through my DSII swap without a hiccup

 

Wow! No wonder no one has answered. That's a tough one. But, I think you do have a clutch going out as the grinding sound is probably slippage under load - like a hill or acceleration.

 

Would be more noticeable in higher gears, so the whole 'in fourth gear' thing makes sense.

Axle seal leaking?
Parking brake hung up?

If you look under the truck do you see that either rear brake backing plate appears damp or wet?
Is there gear oil slung around the inside of the wheels?
Does either wheel or backing plate seem unreasonably hot after driving on the highway?

 

I was afraid you might say that about the clutch At this point, I think I'll take my chances and wait for it to start noticeably slipping, etc. I realize that may leave me stranded on the side of the road at some point, but I don't feel like buying a trans jack and devoting a Saturday to it at the moment.

When I first got the truck, the rear diff was way over-filled and was causing leaking all over the rear axle and up the driveshaft. I drained and refilled it to the appropriate level, cleaned the leaking fluid off to the best of my ability, and the leaking has gone away. That's not to say there isn't still residue hanging around on the axle, backing plates, etc., but it is drying out/going away at this point. Could the smell just be that stuff burning off?

The parking brake appears to work flawlessly (stops the car from moving, but clearly releases with the lever), and I inspected the brakes at all four corners when I first got the truck a couple months ago and it all seemed to be functioning normally. I will check the backing plates next time I get a chance though.

Thanks for the input guys, and any other ideas are more than welcome.

 

If you aren't going to fix the clutch then don't tow or haul anything heavy and if you have to climb a hill shift to a lower gear. That clutch doesn't have long to live.

But, you can buy a clutch kit for ~$100. And a short roll-under tranny jack isn't all that expensive, so you could easily do the job for less than paying someone and have the jack to boot. Otherwise, I'd get AAA Gold so you have 4 tows a year.

 

I won't put it off forever...just going to try and work it into next month's budget

I understand conceptually how to replace a clutch and have the Hayne's manual at home, but any particulars I should be aware of on this truck?

 

You will want another jack to allow you to prop the rear of the engine up, and you can put it under the oil pan but make sure to use a board to spread the weight out.

The clutch kit you buy should have an alignment tool in it, but it not you need to get one. It is just a plastic piece that goes into the end of the crank and ensures the clutch is lined up properly so that you can get the tranny's input shaft to slide through the splines of the clutch and into the pilot bearing in the crank.

And in order to line things up I get some long bolts of the same thread size as the ones that hold the tranny to the engine. Then I cut the heads off and screw them into the engine to act as guide pins.

With some tranny's there is a separate bell housing that comes off, although some have it built in. If they are separate on yours then that's the easiest way to take it apart - pull the tranny and then the bell housing.

When you pull the drive shaft make sure you don't knock the caps off the u-joints. And when you get the drive shaft out from under the truck take the time to inspect the u-joints to make sure they move smoothly. If not you might need to replace them while you have the shaft out.

 

Needless to say, be SURE to have the truck chocked front and rear before you pull the driveshaft.
If just changing a clutch sometimes I shift the gearbox back on the crossmember and never take it down.
One less struggle if you are working alone ( not that I'd recommend that)