doorpz

at least it appears to be coming from the back. its a 83 gsl and i've had it for a little over a year. awhile ago i started to hear a knocking sound from the rear end that increased it loudness and frequency as speed increased. also i was hearing the brakes going bad but didn't really care because i had bought a new car so i didn't drive it so much anymore. so i finally got around to changing the brakes a couple months ago and i knew it was going to be bad, tore up the drivers side drum pretty bad running the shoes all the way down to the metal but i had a spare so no big deal. so i get the brakes all done and i was hoping the knocking was going to go away too but it didn't, not that i really expected it to. always sounded like a bad wheel bearing to me but i never could really narrow down were it was coming from. so today i had some spare time so i thought i would do a little exploring. i know bad u joints can give you a noise/vibration when going bad so i thought i'd try and swap the drive shaft off my junker 85 gs. got the one off the 85 fine but tried to pull it off the 83 and i couldn't get the driveshaft to seperate from the differential, pissed me off so i just put the bolts back in and left it. when i was underneath i kept hearing a noise from the drivers side wheel area when ever i turned the driveshaft, sounded like a grinding or something touching that wasn't supposed to. checked the passenger side and i didn't hear anything. so then i pulled the wheels and drums off to check the play in the axles. on the drivers side i had maybe a 1/4in play when turning back and forth and a very small play pulling in and out. the passenger side didn't have any play either way. would this a be a wheel bearing? doesn't really seem to be to me, i was thinking maybe an axle going bad?(how i don't know) or maybe some problems inside the diff. so i gave up and threw the tires back on and went for a drive. i noticed that now besides the knocking sound i felt a small vibration. so i start doing different things to see what it does. revved it up a little(2k rpms) then dropped the clutch kinda hard and i heard a knock from the rear end. did it again and it knocked a couple times this time. went to turn into a parking spot driving normal and it knocked by itself. now i'm really thinking something went bad in the rear end cause i don't see how a bearing could make noises like that. well i guess thats it for now but any help you can give would be greatly apppreciated, thanks jake

Moonchopper

The added vibration is probably coming from the junker driveshaft you put on. The clunking could be from the axle play when you take the load off and put it back on real quick. At least, that's what I think mine is suffering from.

doorpz

i actually didn't get the other drive shaft on i couldn't get the original one off so i just left it on. how do you fix axle play? change it? i'm thinking about just taking the rear end off the 85 and throwing the whole thing on the 83. it isn't doing anything but sitting and rusting, plus i never had any problems with the rear end before the motor died.

bizarro

iTrader: (1)

could be the bearings gave way and your axle is hitting the axle housing? I say lift the car up as high as you can on the passenger side so your fluid doesn't spill out and pull the axle out just enough to check the bearing there...you'll need an axle pully if you don't already have one...good luck

nopiston_racer

iTrader: (2)

alright this is kinda a shot in the dark....but i had the same problem a while back and i had thought it was either the rear end or the tranny was shot.....come to find out i got underneath the car and i noticed that one of the tranny mounts had lost its washer and nut....this would cause the tranny to drop and make the driveshaft hit the heatshield....and b/c the driveshaft is connected to ur tranny it will sound really really loud inside the car b/c of the vibrations.....if i was u i would definately check this....and also try and check the driveshaft for any spots of wear on it....these would be the areas that its rubbing....hopefully this can help a little....parker

doorpz

yeah didn't really look at the tranny mounts but i'll have to look at them the next time i'm under there. as far as rubbing goes i didn't see any marks on the driveshaft. all the sounds seem to come from the back though so i'm not sure. i know sound can really mess with you sometimes but this last knocking sound i'm sure came from the back of the car cause i stuck my head out of the window and heard it clearly. so does anybody know if there is anything special i would have to do to put an 85 gs rear end on a 83 gsl? i think it would probably just save me some time to just swap the rear end instead of trying to pull this thing apart to find out whats wrong with it. plus the suspension on the 83 is in pretty bad shape and the 85 was in alot better condition.

Siraniko

iTrader: (13)

can someone post a summary? too much reading.

jays83gsl

I'm tired, so I didn't read into it too much, but did you mention the driver's side DRUM on your GSL? I'm confused.

hammmy

He has a knocking in the rear end that increases in volume and frequency with speed. He thought it might be the drum brakes; he replaced those, and the problem persisted. He swapped driveshafts to no avail. He has 1/4" axle play on the driver's side, and none on the passenger. He needs to swap with another drum brake rear end, instead of trying to troubleshoot the axles.

Paragraphs are teh win.

doorpz

yeah i'm not totally sure on the gsl part (badges removed), but i know they are supposed to have rear disc brakes. but yes it does have drums so it must just be a gs. the guy who sold it to me said that only gsl's had sunroofs in 83 not that i totally believed him but this is my first rx7 so i don't know all the small little differences in the years.

t_g_farrell

iTrader: (1)

The play that you describe and the noise when you turn the wheel definitely sound like rear axle bearings. The knock may be something else and you won't be able to tell until you pull out teh axles. Wouldn't be surprised if the axle play is causing the knock when ever load is put on it as someone said earlier. Probably is knocks more turning one direction versus the other. The bearing aren't tha expensive but its not an easy task to change them.

Moonchopper

Ahhh, I think that I might know what it is. The bearing has probably come loose. Either that, or the lock ring came off. Lock rings used to be heated and dropped on the axle; now, they have to be cold pressed. If the lock ring has come loose, then the bearing will definitely be loose, and that would explain your knocking noise when you turn or pick up speed. The bearing is probably wobbling inside, and when you turn, it's throwing the axle a little ways until the bearing catches it. Pull the axle shafts (no need to jack it up just on one side. Very little [if any] fluid will come out if you take the shafts out without draining the oil and leaving it level.)

No need for an axle puller, either. If you have trouble pulling the axles out, just take a hammer to the back side of the rotor. You may not even need to do that, though.

Also, be prepared to take the axles to a mechanic shop with a press. You'll never be able to get the lock ring on without one. You can take the bearing and lock ring off yourself if you want, just use a BFH and a chisel. Break them just enough so you can wiggle it off, and that might save you a couple extra bucks at the mechanic shop. Good luck.

doorpz

so do you think all this work would be worth it since i have an 85 rear end that is is good shape? from what i can see from being underneath the car and from the manual it doesn't look like it would be that hard to just swap out the whole rear end. i might just be making more work for myself but i don't have to spend money on the 85 rear end just time. i have access to a press but the only pressing stuff i've done is u joints. is this something i can do myself? i'm not a total moron when it comes to cars just haven't had a whole lot of experience with rx7's. thanks guys.

GavinJuice

before you go replacing those bearings, just to let you know the proper specs, your rear axle end play should be (0~.0004) or (0~.01)mm. If you have a dial indicator, push n pull on the axle to see what you have.

hammmy

He has a 1/4" of end play. He doesn't need a dial indicator to know that exceeds .01mm.

Moonchopper

Lock rings are not hard to press on, you just have to be very careful. If you did end up replacing the bearings, I would hammer on a long, hollow pipe wide enough to fit over the axle, but small enough so that it would only strike the inner part of the bearing. The bearing can be sat up against the end of the shaft without much trouble. I would suggest getting it seated straight first before pressing anything on, because that would be really bad if you pressed it on crooked. At least, I would think so.