quantum555

whats up, i just recieved my mothers red '91 mustang gt with 95,000 babied miles on it. i know the cars never been abused and would like to do some tweaking to get a little more go. a few problems? to get out of the way first. the check engine light will flash on and off when cruising down the road. it seems to only do it when the gas is being pressed lightly or heavy. anyone have an idea, i have been told it might just be a oxygen sensor. next problem is only one wheel spins when the back breaks loose from a stop. i have been told this may be the rear end getting old. my dad seems to think that new gears in the rear and a new clutch should fix that. any ideas? lastly sometimes when fast shifting into second, the stick will grind just a little even if the clutch is all the way down. any other starter suggestions would be greatly appreciated. thankx</P>


Jeff</P>

mdvaldosta

The O2 sensor generates codes after it goes into closed loop (after it the engine warms on pre OBDII cars), and stays on until the car is turned off. Im not saying thats not your problem, but the best thing to do is to pull your codes and see whats setting off the light. You can either buy a code scanner from a parts store or see if one (like autozon) will check it for you. They only cost about 30 bucks. For your shifting problems, more than likely your 2nd gear sycro's are bad, so your looking at a rebuild... as for the rear end, get a set of 3.73's and throw them in there along with a rebuild kit to fix the worn out clutches in your rear end. That should be all your questions, I hope that helps.

brockleew

I have an 03 GT and second gear always has a small grind either when racing or if its cold. Could be a syncro going bad, but from what Im told its just the nature of the beast. To answer yer question about yer rear end and a bit more feel of power, get 4.10s. Cant go wrong with them.

mdvaldosta

on a 5.0 4.10's would really be tough on the street, they don't rev as well as the 4.6's do, and he could also have smaller tires and rims factory, which would really put the rev's way up there. To each his own though, everyone has thier preferences. I prefer 3.55-3.73 on 5.0's and 3.73-4.10 on 4.6's

quantum555

yea i was thinking the syncro's were going out too, any good place to find the rebuild kit for the rear end, i already have the 3.73 gearsand a person that will install them. is it best to go with motorcraft parts when doing a tune-up or will napa parts work as well?</P>

vfast

tune up only use a dist..cap with brass ends..holley/msd makes some great plug wires...when doing the rear end put all new bearings/seals etc. use red line gear oil when putting a new clutch pak in take 1 or 2 of the best out of the old stack and put with the new set this will tighten up the clutch pack..as for the tranny the t-5 is a weak link as the syco's are very light duty going to a tremec might be right for you as by the sound of it your going to keep the "family car"*L* for awhile and can't wait to abuse it.. if going with a rebuild there a few good deals on e-bay looking a 100-200 parts..pulling the trans will save you a few $$..clutch pak is like $50.00..when puting back in the t-5 you can get a nice 93 cobra clutch less pedal pressure with more holding power..also the quadrant needs a lil attention as the stock plastic deal will let you down..use syth. gear oil in the tranny..hope this helps