KillaVolts

Hey guys..I'm a disabled vet, I'm new here, and really in a tight spot and need some help..Where does it tell me or how do I find out what type of rear end/ diff. gears I have on my car ? Didn't have a manual when I bought it..It's a 04' 40th anniv. GT (Crimson red), with a standard tranny..Also, what is the proper way to check your diff. fluid level and the weight of fluid it has in it? What would happen if you mixed fluids of diff weights?..And finally IF my rear is screwed, whats the "cheapest"/ easiest fix?? rebuild it?..new one?..I keep reading about 8.8 gears?..I'm a vet, and am presently laid off, so cash is a little short..These are the main questions I need help with. The "history" follows, but I don't want to waste you guys time..
I bought the car 3 mos ago w/ 55,00 on it, ran great but made loud humming noise in rear...dealer also said they had to replace pinion seal, so I assume(d) the gears are screwed or smthng. I didn't care as I loved the car and got a great deal on it. Aesthetically it's flawless..We jacked car up level, and a buddy checked it w/finger ( I have a bad back ), said he couldn't feel it, so he added almost a quart of Lucas 80/90W fluid, and said it didn't matter if not the same type as in the car. I have a gravel driveway, and never noticed if it was still leaking after they changed the pinion seal ( I assume it was though since it apparently had no fluid in it), but AFTER we filled it, we put plywood under it and it IS leaking now, and seems to be louder..Am I screwed here?? Should I just plan on replacing the gears? Thanks for ANY and all help guys.. P.S. How do I remove an old post? I started a thread on this the other day but went way overboard, no one responded, and I don't want to waste space on the site..Thx

school boy

welcome to the forums and thanks for your service! depending on how long it was driven with no oil, it could be ruined. if you dont need a performance, buy a low milage 99-04 rear end. if you want a smoother ride for your back, look into a 99-04 cobra irs rear end. irs will handle better stock to stock.

WhiteFoxGT

Sounds like a bad bearing to me. If you're lucky, you can get the bearings re-done and keep the gears. The stock gears in your car are 3.27s. The pinion seal is probably leaking because of the bad pinion bearing, which is making your noise

KillaVolts

Hey whitefox, thx for the reply..I know only basics about rear diff.'s..That used car dealer said they would look at it next wed., replace the seal agin if it's leaking.. Is there anything I should tell them or request of them? I realize it's just advice, so no "liability"..lol..Wondering if I should tell them that when they sold it to me they obviously needed to replace the pinion BEARING as well as the seal maybe?? Try to get them to fix it while it's there? Is that a "major" job?? Since I bought the car "as is", obviously they're not required to do anything, but they seem pretty good about wanting to at least make things right. After all, 12,000 for a car, the rear end shouldn't be leaking, right?..lol..Also, what do you think the best gear oil/ weight would be for a "normal" car like mine? ( although it does have the K & N cold ait intake and fuel injection kit, as well as a Diablosport tuning setup, for which I have the programmer and everyhting that came with it.)..Maybe if they just change the seal I should do a complete fluid change after, or ask them to do it & supply the oil? I'd appreciate any advice..

WhiteFoxGT

if its making noise, no seal will fix anything. Youre wasting your time and theirs if you have them reseal it. Proper way to fix it is get it looked at by a good tech. If the noise is constantly there as soon as you start moving, its a bearing. If the noise is only between 40-60mph on throttle or coasting, its a ring and pinion. ring and pinion noise isnt something you HAVE to fix. A bearing noise however will get worse and eventually fail. Any bearing in the rear is a big job, especially the pinion bearing. Requires complete disassembly.

KillaVolts

Hey fox.thx again..(1)So you think it's probably the bearing then ?.. because the noise/ vibration is there at ALL speeds, but it's loudest around 50mph..Actually, you really can't so much HEAR it at very low speeds, but you can FEEL it...even if I'm rolling at 5 MPH with the clutch in, engine revs down ( like rolling up to a red light ), it feels like I'm driving over rough concrete ( kinda like a truck with knobby tires feels)..It would make sense since when I bought it they said they needed to replace the seal.. I bet whoever they got it from probably let it get too low and f'd up the gears..so they just did the minimum to sell it and replaced the seal so it wasn't leaking..I wonder why it's leaking again tho, if they DID replace the seal..Would a bad bearing do that ( premature seal failure)? Either way, I'm hoping once I bring it to them Wed., I can convince them that they should fix my rear end correctly, or pay to have it done. Since they acknowledged the noise before I bought it, if the bearing IS bad, then they sold me a car that was theoretically dangerous to drive ( I live in Maine, and they have pretty strict laws regarding that stuff here I'm told)..
Also, I was thinking maybe the prev. owner ( since he DID do those prev. listed mods, plus an eibach kit) DID change out the rear to that 8.8 I keep reading about, which is supposedly famous for gear whine, or something else..(2) Could I tell that from the diablo tuner interface? I've never plugged it in yet, but from reading the manual it seems you can see which changes were made..If he DID change the rear, he would've used that to adjust for it, no? Maybe that can tell me something..Thanks again, enjoy your weekend Fox..

WhiteFoxGT

Your car has an 8.8 rear in it. So lets get past that already. You have a bad bearing in the rear. Plain and simple. If your lucky, the ring and pinion is still ok. You won't know until you tear it apart. Same thing with the gear ratio. It's possible the previous owner changed it. The tuner can be used to correct the speedo. You need to have it properly diagnosed and repaired. Fixing a leak will do nothing

KillaVolts

Fox, in your first response, you said the stock gears were 3.27s in my car..So I kept wondering about the 8.8..Now you just said " your car has an 8.8 rear in it, so lets get past that already"...As I said in my first post, I know nothing about rear differentials, so I didn't ( and don't ) realize the difference or relation between those numbers ! I also said that I am laid off ( from one of the few jobs you can do in my condition), and money is beyond tight, so bringing it somewhere is out of the question! My only hope right now is the place I bought it, which is why I was asking what i should tell or ask them..I myself haven't been under a vehicle since I took a mortar round to the back in Desert Storm..Basically I'm ****ed and wanted some clue as to my options.. Sorry to bother you..

WhiteFoxGT

You're not bothering me. The gear ratio is 3.27. The size of the rear is 8.8. The size does not = the gear ratio. And i understand the money issue, trust me. However, that is whats wrong with your diff..Im positive. Just giving you a heads up