Bad Odor: Please Help! - Ford Forums

djporters · 01-08-2002, 12:56

I have a 66 GT fastback and recently had the rear end gears replaced to the original gears (3.50?). Since then, I have noticed an odor that smells like heavy gear oil or grease when I am driving. I am not exactly sure if that is the correct source of the odor. I took the car back to the mechanics and told them of this problem so they checked out the rear end. There were no leaks or problem areas that they could find and they could not suggest an alternative source of the smell. We then checked out the front of the car and the mechanic suggested that the smell might be coming from the grease that is in the gear box (?) and since I have headers he suggested that the headers might be causing the smell. Interstingly, there was no grease on the headers nor was there any burn marks as well.
What concerns me about his theory is that this smell was never there UNTIL they replaced the rear end gears. This makes me think that there is a connection w/ their work and the smell. Then again, it just might be a coincidence.
I would really appreciate any help, suggestions, or theories that you may have so that I can resolve this issue. By the way, the smell seems to increase or become apparent when the car is warmed up.

ZoNiE · 01-08-2002, 14:40

You might very well be right about the "connection" between them finishing their work and the smell. I just finished, as well, swapping the gear ratio on mine and as clean as I kept it, I still get a "whiff" of something in the air after running the car. A thin layer of gear oil from a finger print(s) either from them touching the exhaust or the axle housing would be enough and might take awhile to dissapate. Gear oil is one of the most vile smells around and the hardest to clean up from. This is coming from a person who has a "clean" garage and after 3 days the smell of gear oil still lingers. From the same person who scrubbed himself "raw", and I mean "raw", and went to bed the same night after the change only to have the wife kick me out because I smelled like gear oil. Yes, even today (3 days later) in the heal of my hands I still smell like, you guess it, gear oil.

However, I would do a spot check from time to time, just to make sure you're not leaking the gear oil. Of course check the housing as well as the backing plates for the brakes. If you still smell it after, say, 200 to 300 miles, take it back to them to check the steering box again (not likely the problem though). Make sure this time, just for the fun of it, to have them take the brake drums off to inspect for gear oil on the linings.

Just my suggestion! Now if you excuse me, I'm going to grab the "Purple Power" and go clean my axle housing from any oily finger prints I might have left behind.

SuperDave · 01-08-2002, 15:10

Damage to the rear axle seals might have occured when the axles were removed. Gear oil may be getting on the brake shoes and as they are warmed, the smell may be more evident.

djporters · 01-13-2002, 17:48

Zonie & Superdave, thanks for your input. I took the car in to the shop and found out the rear shock plugs were missing from the car. Apparently the rear end has a tube that is used as a means of preventing any build up in the end and is placed into the frame area for venting. After we put in original plugs (not the after market plugs that do not fit as snugly) the odor seems to have stopped. This of course was great news considering the odor that was present whenever I drove the car. I think that has solved the problem; thanks once again all.