Squeeeaaaling Tranny
05-28-18, 11:42 AM
#1
Full Member
Thread Starter
Squeeeaaaling Tranny
So I finally got around to an engine rebuild for my '84 SE last month, and I drive it about 250 miles with no issues. Then over the course of a short drive, it begins squealing as I get going from a stop into 1st gear, and I smell burning clutch like crazy. Then a few minutes later, it starts doing it when shifting from 1st to 2nd, and 2nd to 3rd. Then almost immediately after, it starts squealing and burning clutch even with the clutch all the way out, in any gear, and so I throw it in neutral and stop the car. All within the span of a few minutes. I have it towed to AAMCO, and they say I need an entire trans rebuild. They quote me really high, so I have it towed to another well-regarded transmission shop who also tells me I need a rebuild. Ok, fine. They install an Exedy Stage 1 clutch kit that includes a new disc, spring hub, throwout bearing, and pilot bearing, plus a new lighter Racing Beat flywheel and Mazda rear counterweight.
I get the car back, and it seems fine on a five-minute drive home. I drove it for the second time today since the rebuild on a 30-mile ride, and toward the end it starts squealing when I get going from a stop into 1st gear. Then soon after, it begins squealing in 1st gear even with the clutch all the way out. I'm right near my house so I throw it in neutral and coast home. Here's the new thing I noticed today: the car squeals even when I rev it in neutral. What's left that it could be? Tranny input shaft bearing? Something with the clutch fluid? Fluid was bled and filled up, though, and I haven't noticed any obvious leaks. Whatever it is, the car's been through two transmission shops and one Mazda shop, and none have been able to figure it out. Any idea?
I get the car back, and it seems fine on a five-minute drive home. I drove it for the second time today since the rebuild on a 30-mile ride, and toward the end it starts squealing when I get going from a stop into 1st gear. Then soon after, it begins squealing in 1st gear even with the clutch all the way out. I'm right near my house so I throw it in neutral and coast home. Here's the new thing I noticed today: the car squeals even when I rev it in neutral. What's left that it could be? Tranny input shaft bearing? Something with the clutch fluid? Fluid was bled and filled up, though, and I haven't noticed any obvious leaks. Whatever it is, the car's been through two transmission shops and one Mazda shop, and none have been able to figure it out. Any idea?
05-28-18, 12:05 PM
#3
1st, get your RX-7 away from AAMCO. Of course they said you need a rebuild, That's the guy's job at one of those huge chains.
It almost sounds like the fuel pump, A/C or alternator pulley bearing is on it's way out. How tight are those belts? Too tight is as bad as not tight enough.
Here's a rotary shop near you.
RotorSports Racing Mazda RX-7 rotary engines and performance modifications shop
It almost sounds like the fuel pump, A/C or alternator pulley bearing is on it's way out. How tight are those belts? Too tight is as bad as not tight enough.
Here's a rotary shop near you.
RotorSports Racing Mazda RX-7 rotary engines and performance modifications shop
Last edited by Natey; 05-28-18 at 12:10 PM.
05-28-18, 12:11 PM
#4
Full Member
Thread Starter
You know, that's a good idea to check the belts. I put on new belts and got the tension perfect not long ago, but one of those shops might have fiddled with those brackets and I bet they didn't take the time to tension them properly. I didn't think about that until you two mentioned belts. I'll go take a peak this afternoon when it stops raining.
05-28-18, 01:11 PM
#5
84SE-EGI helpy-helperton
Check your water pump pulley for play. When the bearing fails, it will squeal from internal rust, and may not have worn through to the weep hole, yet which would indicate through leaking coolant down the front of the engine. Belts are an important part of maintenance on these cars and should be balanced for tension across the main pulley. Note that you hve Power Steering on an SE most likely, which is another belt and pump to check, which can result in squealing...
06-07-18, 12:06 PM
#6
Full Member
Thread Starter
Long while since an update, but I did finally check out all the belts. One of the shops fiddled with the alternator belt; it was so lose I could play it like a harp. I re-tensioned that and checked the others. The air pump and A/C belts were fine; my SE has manual steering, so no PS belt to check. I just got a chance to give it a long drive, and while most of the squealing is gone and it sounds much better, there were still a few moments of squeal, even going from 4th to 5th gear and revving it in neutral. I'll check out the pulleys tonight. I did replace the water pump not long ago, though.
Last edited by Maroochy; 06-07-18 at 02:12 PM.
06-07-18, 04:33 PM
#7
ancient wizard...
Just looked at this thread 1st time. Surprised no one yet has figured it out. Op has included several important clues as to origin of problem.
Though I haven't driven/heard his car,strongly suspect trans overhaul? was unwarranted. Always nice to upgrade clutch/flywheel but they're also not cause of problem.
The culprit is most assuredly the fan clutch which is certain to be 80-100% locked up allowing fan to rotate on 1to1 ratio with water pump hub. My guess is it takes 16-18 hp or more at hi revs,even cruising speed. Few appreciate how much pitch the fan blades have and how much power it takes to turn it in full locked mode.
Suggest op warm up and take car for a ride to duplicate squealing noise. Pull over and with a 10mm wrench,remove complete fan/clutch assembly from water pump hub. There is just enough room to remove it and take it out of engine compartment,throw it in back of car and drive the crap out of it. No more squeal and it'll feel like it has more power because it does as the fan is no longer siphoning it off.
Do not let idle or drive slower than about 25 mph or it'll start to get hot. Above that speed fan not necessary as car moving forward forces enough air thru rad to cool it.
More than a few years ago I had a very similar scenario that started after a period of stop and go traffic due to an accident ahead.
When I accelerated back up to speed there was a howl from underhood and car had list some zip. Pulled over 1st chance,opened hood and grabbed throttle linkage to rev up engine. Car temp was normal at this time but fan clutch was fully locked up.
Shut car down and could turn fan but not as smoothly as previously.
Continued to drive,in a matter of miles the squealing/burning rubber smell was overpowering. I was short shifting to keep rpms low as possible. Then noticed batt voltage dropping off. Pulled over again and alt belt could about be removed by hand it was so worn out. All belts were good when pretrip checked car. Stopped and got a couple belts at parts store and put one on.
As I recall it lasted about 40 miles at highway speed before it too was smoked.
Now about midnight and @400 miles to get home,I decided to remove fan/clutch assembly and drive without it. On highway/turnpike it was fine,stuck in traffic I would pull over put fan back on til traffic cleared out then pull over again and take it off. This is how I got home,fortunately the earlier in morning it got the less traffic there was and didn't have to go fan r&r as much.
Op I have doubts anyone fiddled with your alt belt tension,my take is locked fan clutch smoked(burning smell) belt and has worn it prematurely.
Inspect closely around pulleys on alternator (front of alternator),water pump,main pulley,front of engine for bits of rubber stuck in these places that cane from the belt. Looks just like rubber stuck to rear wheel well in car just out of burnout box at drag strip.
If it's not fan clutch which I think it is,remove all belts and spin accessories and listen/feel for rumble or growl from bad bearing.
Can also put long screwdriver on each accessory with engine running and put your ear to handle and listen for same.
Post back what you find and what the fix was.
Though I haven't driven/heard his car,strongly suspect trans overhaul? was unwarranted. Always nice to upgrade clutch/flywheel but they're also not cause of problem.
The culprit is most assuredly the fan clutch which is certain to be 80-100% locked up allowing fan to rotate on 1to1 ratio with water pump hub. My guess is it takes 16-18 hp or more at hi revs,even cruising speed. Few appreciate how much pitch the fan blades have and how much power it takes to turn it in full locked mode.
Suggest op warm up and take car for a ride to duplicate squealing noise. Pull over and with a 10mm wrench,remove complete fan/clutch assembly from water pump hub. There is just enough room to remove it and take it out of engine compartment,throw it in back of car and drive the crap out of it. No more squeal and it'll feel like it has more power because it does as the fan is no longer siphoning it off.
Do not let idle or drive slower than about 25 mph or it'll start to get hot. Above that speed fan not necessary as car moving forward forces enough air thru rad to cool it.
More than a few years ago I had a very similar scenario that started after a period of stop and go traffic due to an accident ahead.
When I accelerated back up to speed there was a howl from underhood and car had list some zip. Pulled over 1st chance,opened hood and grabbed throttle linkage to rev up engine. Car temp was normal at this time but fan clutch was fully locked up.
Shut car down and could turn fan but not as smoothly as previously.
Continued to drive,in a matter of miles the squealing/burning rubber smell was overpowering. I was short shifting to keep rpms low as possible. Then noticed batt voltage dropping off. Pulled over again and alt belt could about be removed by hand it was so worn out. All belts were good when pretrip checked car. Stopped and got a couple belts at parts store and put one on.
As I recall it lasted about 40 miles at highway speed before it too was smoked.
Now about midnight and @400 miles to get home,I decided to remove fan/clutch assembly and drive without it. On highway/turnpike it was fine,stuck in traffic I would pull over put fan back on til traffic cleared out then pull over again and take it off. This is how I got home,fortunately the earlier in morning it got the less traffic there was and didn't have to go fan r&r as much.
Op I have doubts anyone fiddled with your alt belt tension,my take is locked fan clutch smoked(burning smell) belt and has worn it prematurely.
Inspect closely around pulleys on alternator (front of alternator),water pump,main pulley,front of engine for bits of rubber stuck in these places that cane from the belt. Looks just like rubber stuck to rear wheel well in car just out of burnout box at drag strip.
If it's not fan clutch which I think it is,remove all belts and spin accessories and listen/feel for rumble or growl from bad bearing.
Can also put long screwdriver on each accessory with engine running and put your ear to handle and listen for same.
Post back what you find and what the fix was.
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06-07-18, 07:16 PM
#8
Full Member
Thread Starter
Good idea to check the fan. I'll take a look at that tomorrow. Once I noticed the squealing happened in neutral too, I figured I should start looking underhood for the problem and not in the tranny. That was after the rebuild, though. I was a little doubtful of needing the rebuild, but I liked having an excuse to upgrade all the tranny bits. If anyone is thinking of the aluminum flywheel for a daily driven RX - at least a fuel-injected SE - do it. You'll love it. Not tricky to drive at all.
06-08-18, 05:45 AM
#9
As stated above, the fan clutch is prone to failure and will cause the issues listed above. When checking the fan clutch and checking the bearings on the water pump, air pump, and ac compressor, make sure that you check the belts themselves for abnormal wear, cracking and glazing. Bad belts themselves will contribute to noise as well and can squeal. Just ttrying to help you cover all of you bases.
06-10-18, 03:33 PM
#11
Full Member
Thread Starter
It sounds exactly like that. I'm noticing it only does it after the car is warmed up and I've been driving for a while. That turned out to be your alternator belt, right?
This thread needs a title edit to something else.
This thread needs a title edit to something else.
Last edited by Maroochy; 06-10-18 at 04:56 PM.
06-10-18, 10:25 PM
#12
Junior Member
I did notice one belt with cracks upon initial inspection.
06-11-18, 08:39 AM
#13
ancient wizard...
Replace the belts!
Why drive car in this condition any longer than it takes to get "home". Same for OP,have way more $ in trans work in attempt to fix this than cost of a set of belts.
Post back results after doing so and putting some miles on to verify fix,or recurring squealing. (Both posters) look for rubber dust around pulleys,once belts are off,should be easy to identify which was slipping.
Resist temptation to tension drive belts-old or new-tighter than needed in an attempt to stop slipping/squealing. This causes premature wear to front eccentric shaft bearings,alt,and water pump bearings.
Proper belt tension with new belts is achieved with 1/2" or 13mm deflection on longest run of belt between pulleys.
Why drive car in this condition any longer than it takes to get "home". Same for OP,have way more $ in trans work in attempt to fix this than cost of a set of belts.
Post back results after doing so and putting some miles on to verify fix,or recurring squealing. (Both posters) look for rubber dust around pulleys,once belts are off,should be easy to identify which was slipping.
Resist temptation to tension drive belts-old or new-tighter than needed in an attempt to stop slipping/squealing. This causes premature wear to front eccentric shaft bearings,alt,and water pump bearings.
Proper belt tension with new belts is achieved with 1/2" or 13mm deflection on longest run of belt between pulleys.
06-15-18, 08:58 PM
#15
Full Member
Thread Starter
Just had a garage open up at my apartment, so I'm moving the car in there tomorrow and will be able to take a better look at this. My belts are only 500 miles old, if that. I checked them out before I installed them and didn't see any abnormalities or damage, but it may be worth a new belt just to swap it out anyway.
07-17-18, 06:37 PM
#16
Junior Member
Just had a garage open up at my apartment, so I'm moving the car in there tomorrow and will be able to take a better look at this. My belts are only 500 miles old, if that. I checked them out before I installed them and didn't see any abnormalities or damage, but it may be worth a new belt just to swap it out anyway.
08-14-18, 08:31 PM
#17
Full Member
Thread Starter
I so wanted to come back on here with good news. I did get a new alt belt for it. I'd noticed parts stores were recommending Bando part# 2320, which is a 9.5x820 belt. That doesn't sync up with my records showing that the car, from the factory, needs a 9.5x800 belt (Bando part# 2315), so I did replace that with a 2315. I cleaned up all the pulleys while the belts were off, then replaced everything and torqued it all down with the proper belt deflection amounts according to the FSM.
I took the car for a drive and it was a lot better. For about 20 minutes, from city driving to 80 MPH. Then I got a wee bit of squeal at 4k RPM and some burning smell. I kept it below 3.5k RPM on the way home and didn't hear any more squeal, but it was disappointing. It could be a bad pulley, but the squeal goes away when the belts are re-tightened, and then the squeal appears are it's been driven for a while, like the belts keep loosening up while driving.
I took the car for a drive and it was a lot better. For about 20 minutes, from city driving to 80 MPH. Then I got a wee bit of squeal at 4k RPM and some burning smell. I kept it below 3.5k RPM on the way home and didn't hear any more squeal, but it was disappointing. It could be a bad pulley, but the squeal goes away when the belts are re-tightened, and then the squeal appears are it's been driven for a while, like the belts keep loosening up while driving.
Last edited by Maroochy; 08-14-18 at 08:41 PM.
08-14-18, 09:17 PM
#19
Junior Member
My squeal went away after replacing my crumbling fan. The new fan came with a clutch. Could tell before installing it would work. The old fan spun easily when warm out, the new fan was easy to turn in air conditioned house, got harder to turn out in the warm.
I can hear the fan kicking in again, forgot the sound. Like an old CJ7 jeep. This baby is running smooth again.
I can hear the fan kicking in again, forgot the sound. Like an old CJ7 jeep. This baby is running smooth again.
08-14-18, 10:52 PM
#22
ancient wizard...
Fan clutch for SE is discontinued. Order this # N 249-15-210 B. This is still available thru Mazda,best price online $219. Atkins Rotary has in stock for $266 Part is for a 12 A car. It will fit your SE and work fine. I have one on my SE for about 7 years now.
When you replace it,you'll see how much the fan has been eating horsepower(and belts) by how much zippier the car runs. Probably see a bump in fuel economy too.
When you replace it,you'll see how much the fan has been eating horsepower(and belts) by how much zippier the car runs. Probably see a bump in fuel economy too.
