murben

So I am now in the process of dropping the transmission to change the clutch on my 85 GSL (clutch is slipping pretty bad). I haven't got it dropped yet, but am seeing some oil on the bottom of the trans where it meets the motor, so am assuming that it's got a leak from the rear main seal which is ultimately the source of my slipping clutch. So, my question is, how difficult is it to change the rear seal, and am I going to need any special tools to do it?

j9fd3s

iTrader: (3)

its easy to change, all you really need is the 2 1/8" socket to get the flywheel nut off.

you should change the rear main since you're in there, but i also could be leaking from the oil pan, or the front of the trans, so just look things over when its apart

coldy13

Oil down there could be from the oil cooler/filter too. Only way to tell is to look and see where its coming from. You see it on the bottom, trace the wetness up until you find the source. A mirror on a stick and a flashlight can be helpful for this, not really needed on these cars though.

To change the rear seal I think you're supposed to take off the rear stationary gear, 6 bolts under the flywheel, and press the seal out and back in. If you're careful you can stab it with a pick and pry it out, then tap the new one in. If you do it the easy way and you're not careful don't be mad when you scratch the e-shaft and it won't ever seal again.

murben

I'm just trying to prepare for the worst. I'm assuming when I finish getting the transmission out, I'll know pretty quickly whether or not it's the rear main seal. Anyone know what the part number for the seal is? I'm looking on RockAuto and can't seem to find it.

Also, looking on RacingBeats site, they have a few tools specifically for getting the flywheel off. Any of those tools necessary or worth the money?

81WideMariah

iTrader: (8)

honestly, I can't think of a good way to change the rear seal without pulling the engine from the car... picking it out will be frustrating, and dangerous to the e-shaft. Probably best to pull the engine.

If you have air tools, get a 2 1/8" socket and use an impact to pull the flywheel nut off. You'll need a flywheel stopper, mazdatrix sells a great one for cheap. If you don't have air tools, buy the RB flywheel wrench.

DriveFast7

iTrader: (1)

you can remove the rear stationary gear without disassembling the motor. Just don't turn the eccentric shaft with the gear out.

mazdaverx713b

iTrader: (91)

don't assume your slipping clutch is caused by oil on the disc. order a new clutch kit which will include the disc, pressure plate, and throwout bearing. you will also want to order a new pilot bearing and seal as well.

the part number for a new rear main seal is 1668-10-556A

clykins

iTrader: (1)

I just replaced the rear main seal on my 85 GSL 12a. Once the flywheel is off the rear main seal comes out easily with a large screw driver. You don't need to remove the rear stationary gear.

clykins

iTrader: (1)

Like Mazdaverx713b said, you will most likely need to replace the pilot bearing as well. Good luck with that. Mine was a real pain to remove. Installation though was simple with a similar size socket.

LongDuck

Not to circumvent the thread, but a word on Pilot Bearings, since you're going to have yours visible;

1) the PB, as long as it's been lubed and has the grease seal cup in place, is fine to leave in there unless it's making noise. Many people try to replace a perfectly good PB, only to waste hours trying to get the old one out, press in a new one that's no better than the old one, just to have it done. It's unnecessary - unless - you hear the 'whirring' with the engine running and the clutch pressed IN with the transmission in any gear. It'll whirr until it grenades, and then it goes silent.

2) sometimes after the PB grenades in there, and you won't find a grease seal or any of the roller bearings, just fine powder. Unfortunately, the purpose behind a PB is to locate the input shaft of the tranny to the center of the flywheel to avoid harmful vibration, so you need one in there. Usually, the grenaded PB leaves it's outter race inside the E-shaft, and the best approach to remove it is with a chisel and hammer, cutting the race carefully to split it and allow it to be twisted out.

3) careful replacement of the PB means greasing the E-shaft hole liberally, then sliding the new PB in as far as you can, then using a socket of similar size to drive it slowly into place. Regrease the PB rollers from the inside, and then grease the grease-seal and insert it just before you put it all back together. Grease Seals and PB's fail because of not having enough grease - so don't be stingy with the stuff.

Also, it could just be that your clutch is worn excessively resulting in slippage, in which case, you don't need to mess with the engine rear seal or stationary gear. When you get the clutch disk out, measure it's thickness against a replacement clutch disk and you can tell if it's worn.

My 84SE leaks so much oil from a bad oil pan gasket that the bottom of the car is thoroughly water-proof, but it has yet to cause any problems with clutch slippage. It leaks enough that when I jack the car up on one side, you can see the oil running to the far side to create drips...

Point being that this could be a simple clutch replacement instead of major surgery like you're expecting. HTH,

murben

Thanks for all of the responses. I have ordered the street-comp clutch from Rotary Performance's web site as well as the bearing kit to replace all of the bearings while I'm in there. They also offer rental of the Mazda pilot bearing removal tool for $15 (with a $100 deposit) and say it makes the replacement of the pilot bearing very simple so I'm getting that as well. Everything is supposed to be here tomorrow, and I'm hoping to do the job this Saturday. I'll let you know how it goes.

On the oil leak, I took everyone's advice and looked at it a little closer and it does actually look like it's coming from somewhere below the oil filter, running down the side, and ending up on the bottom of the engine/transmission. So I'm really hoping that's the only source and I won't have to mess with the flywheel/rear main seal.

mazdaverx713b

iTrader: (91)

the issue that you're seeing under the oil filter is faulty oil pedestal o-rings. there are four total and i can provide the part number if you'd like to replace the o-rings.

murben

That would be great if you could give me the part numbers! Thanks.

j9fd3s

iTrader: (3)

9954-10-1601 is the mazda number. an 85 GSL takes 4.

Jeff20B

iTrader: (13)

Mazdatrix direct link: http://www.mazdatrix.com/getprice.as...m=10-1601-9954

murben

Thanks for everyones help on this. I lucked out and the rear main seal was not leaking. The clutch plate was in terrible shape, was as smooth as a brake rotor. New clutch is in and everything is back together except for the exhaust.