Rear axle play problem
05-10-15, 02:30 PM
#1
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Rear axle play problem
First a short version of the story behind my car: I lost my S4 Turbo II in a fire caused by a leaking fuel line about 2 years ago and bought a NA Miata. It is a nice car and really fun to drive but I really missed the rotary engine and I never really stopped searching for an interesting project RX7 and 3 weeks ago i finally found it on Ebay.
I'm going to make a thread about it but for now I'm in need of some fast suggestions and advices. 3 teaser pictures:
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Yes, it's a BAE turbo with water-methanol-injection and as far as I know it's the only one running in Germany.
Ok enough of the backround story for now. I'm having serious problems with the rear axle. I found out the previous owner must have hit a curbstone with the right rear wheel. The wheel itself had a big dent. I have 5 of them so I was able to change the bent wheel against the spare wheel but something seems to be damaged inside the axle. When I turn right I sometimes get a loud "clonk" from the right side of the axle where the damaged wheel was. Sometimes it even sounds like grinding gears (the kind of grinding you would expect coming from 2 gears which have too much play and nearly slip over) for a second. It sounds really unhealthy. I only can imagine there is some movement inside the axle from side to side which normally shouldn't be there.
I never had to deal with a rigid axle before so I really need some advices what to do now.
Some additional informations on the axle and the car: The car is a 1980 SA which was bought by a big Mazda dealership and build by them in cooperation with a company called "Kahn Turbosysteme" from 1980 till1982 for hillclimbs and i guess street rallyes. It has got a limited slip differential inside and disk brakes and I have a bill saying it was ordered from Mazda in 1981 which is pretty amazing because as far as I know there weren't any official RX7 models with a LSD in 1981.
I'm going to make a thread about it but for now I'm in need of some fast suggestions and advices. 3 teaser pictures:Yes, it's a BAE turbo with water-methanol-injection and as far as I know it's the only one running in Germany.
Ok enough of the backround story for now. I'm having serious problems with the rear axle. I found out the previous owner must have hit a curbstone with the right rear wheel. The wheel itself had a big dent. I have 5 of them so I was able to change the bent wheel against the spare wheel but something seems to be damaged inside the axle. When I turn right I sometimes get a loud "clonk" from the right side of the axle where the damaged wheel was. Sometimes it even sounds like grinding gears (the kind of grinding you would expect coming from 2 gears which have too much play and nearly slip over) for a second. It sounds really unhealthy. I only can imagine there is some movement inside the axle from side to side which normally shouldn't be there.
I never had to deal with a rigid axle before so I really need some advices what to do now.
Some additional informations on the axle and the car: The car is a 1980 SA which was bought by a big Mazda dealership and build by them in cooperation with a company called "Kahn Turbosysteme" from 1980 till1982 for hillclimbs and i guess street rallyes. It has got a limited slip differential inside and disk brakes and I have a bill saying it was ordered from Mazda in 1981 which is pretty amazing because as far as I know there weren't any official RX7 models with a LSD in 1981.
05-10-15, 03:18 PM
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neat car!
for the rear axle, we don't have a European parts catalog, but we do have the sales info. it seems that the European spec cars got rear discs as standard when they became available in 1981, with an open diff only. in the US and Japan, the rear discs were optional, but when they were fitted LSD came with them.
there was also a competition setup that was available from 1979 onwards, its a different axle housing, limited slip, and unique calipers and discs. part number would help here, the 4352 is competition. pics would also work
actually working on the thing is really simple, pull a wheel off and see if there is play
for the rear axle, we don't have a European parts catalog, but we do have the sales info. it seems that the European spec cars got rear discs as standard when they became available in 1981, with an open diff only. in the US and Japan, the rear discs were optional, but when they were fitted LSD came with them.
there was also a competition setup that was available from 1979 onwards, its a different axle housing, limited slip, and unique calipers and discs. part number would help here, the 4352 is competition. pics would also work
actually working on the thing is really simple, pull a wheel off and see if there is play
05-10-15, 03:42 PM
#3
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My car is absolutely strange. It definitely is a 1980 model. It was first registered in april 1980. Buuuuut the rear end allready has the newer taillights of the 81 model.
Where can i find that number? By the way I was told the Mazda dealer upgraded the axle because the original axle couldn't hold the power and more or less exploded while testing the car the first time.
I can tell I have a strange amount of play at the drive shaft. I can turn it about a quarter turn before the wheels start moving. But again: I'm not really familar to rigid axles so I don't know if that might be normal.
I allready pulled the wheels off but there is no play at all. Only the strange drive shaft play.
Are there still parts available for the competition version if mine is one of those? Do you have any more informations about that axle?
My biggest problem is I don't know the full story behind the car. I'm trying to find out as much as I can but the Mazda dealer (still existing) doesn't really want to talk about the car. I know they had some bad luck with it. They built it and when it was done they recognized there was no racing class for it in Germany back in 1982. That's the reason why it only has 25000 miles on the clock.
Sound's totally stupid but that story is confirmed. I guess that's why nobody wants to talk about the RX7 there.
Oh by the way I just remembered a thing about the transmission: It's spur-toothed (hope that's the word). Was that some kind of mazda competition series, too?
Where can i find that number? By the way I was told the Mazda dealer upgraded the axle because the original axle couldn't hold the power and more or less exploded while testing the car the first time.
I can tell I have a strange amount of play at the drive shaft. I can turn it about a quarter turn before the wheels start moving. But again: I'm not really familar to rigid axles so I don't know if that might be normal.
I allready pulled the wheels off but there is no play at all. Only the strange drive shaft play.
Are there still parts available for the competition version if mine is one of those? Do you have any more informations about that axle?
My biggest problem is I don't know the full story behind the car. I'm trying to find out as much as I can but the Mazda dealer (still existing) doesn't really want to talk about the car. I know they had some bad luck with it. They built it and when it was done they recognized there was no racing class for it in Germany back in 1982. That's the reason why it only has 25000 miles on the clock.
Sound's totally stupid but that story is confirmed. I guess that's why nobody wants to talk about the RX7 there.Oh by the way I just remembered a thing about the transmission: It's spur-toothed (hope that's the word). Was that some kind of mazda competition series, too?
Last edited by Th0m4s; 05-10-15 at 03:47 PM.
05-10-15, 06:11 PM
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i think its been updated, its SA interior
05-10-15, 07:11 PM
#6
You might have shattered the bearing. When my wife got her MX-5 the PO hit a curb and shattered the bearing and the rotor.
As for the clunk sound, it might be in the 3rd member or your halfshaft might be bent. You'll have to pull the axle to find out.
As for the clunk sound, it might be in the 3rd member or your halfshaft might be bent. You'll have to pull the axle to find out.
05-11-15, 03:26 PM
#7
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I don't think the halfshafts are bent because my problem only happens in right turns. When i drive straight everything is working like it should.
I've looked up the repair manual and parts catalog and found something which might cause my problem but I'm not 100% sure about that. Every RX7 1st gen differential has 2 parts with the number 27301A according to the parts catalog. The description says "screw-adjust" and it looks like those parts are holding the whole differential assembly on it's position inside the housing and if one of them went loose everything could move to the left or to the right. Am I thinking in the right direction?
I've looked up the repair manual and parts catalog and found something which might cause my problem but I'm not 100% sure about that. Every RX7 1st gen differential has 2 parts with the number 27301A according to the parts catalog. The description says "screw-adjust" and it looks like those parts are holding the whole differential assembly on it's position inside the housing and if one of them went loose everything could move to the left or to the right. Am I thinking in the right direction?
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05-11-15, 04:29 PM
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27-301A is an adjuster, it lets you move the ring gear side to side, relative to the pinion.
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