Hello to all, I am a new member, I have had an 87 for three years and love it. I just got an 85 a few weeks ago, it was a california car, no power steering, no ac, no sunroof. The guy had just put a new clutch, starter, distributor, and wires on it but when the clutch master cylinder went out he parked it. It is in good shape, exept for 3 passenger side moldings and some minor dings. I changed the CMC but damaged the u-joints joy ridin' that weekend so I had to change the driveshaft. I got it for 700$, I thought that was pretty good, but Its got alot of miles. It runs ands drives great. Anyway I'm replacing the diff seal and I was wondering about recommendations on the best fluid for the rearend to help preserve it because it is pretty whiny in the midrange speeds. I also like the buzzer better than the shift light, its just cool.

 

welcome to the forum.
As far as gear oil, I have always had good luck with Neo Synthetic. I have heard many good things about Torco and Redline gear oils as well. If it's making alot of noise then chances are nothing is gonna make that much better.

 

Welcome and congrats on the purchase. Sounds like you have the base 'G' model, as I'm pretty sure that the GS model came std with the sunroof, and I know that the GSL did. Personally, I prefer not having the roof, better rigidity and less rattles. Like FD racer said, any good synthetic will work in the diff, but nothing will reverse damage, of course.

You might have luck finding a replacement diff at a local boneyard if the diff is indeed on the way out. If you happen to stumble across a GSL with rear disc brakes, you could swap the whole assembly in with an added bonus of a limited slip differential. Check out the FAQ at the top of the page for details.

 

as i understand it there is no seal unless you use liquid seal, check if the diff bolts are just loose...mine were and i tightened and done...no leaks...careful though, not too tight or else you'll snap the bolts

my diff is noisy too, but lots of these are...so i've heard...i just replaced the fluid with redline, it quieted down a little bit...not much though...but redline is definately a GREAT product...get it for your tranny and you'll feel a night and day difference!

 

Mazdatrix recomends redline. Go to their page and read up, good info. And welcome!

 

Thanks for the advise, I think I will try redline and I will also try to tighten the bolts to maybe stop the leaking, I like free fixes. This gen 1 definitely has much less interior rattles compared to the gen 2, but that may be from the bad roads I have to travel sometimes

 

"Welcome and congrats on the purchase. Sounds like you have the base 'G' model, as I'm pretty sure that the GS model came std with the sunroof, and I know that the GSL did...."

Actually, the sunroof was also an option on the GS. It just happens that most have sunroofs. I have two non-sunroof 85 GS cars.

 

Cool, I was'nt sure what the model was but that definitely sounds right, It is definitely as base as it gets, but thats all good to me. Except for when I'm sweating my *** off in the texas heat this summer, but I'll just drive faster!