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I have dropped my transmission due to some bearing noise and opened a small can of worms. Turns out the clutch, flywheel, and pressure plate are pretty worn out so I got a new clutch and flywheel on the way but I have also noticed that there are no needles in my pilot bearing... there was just grease but no bearing surface for the input shaft to ride on. Now I doubt there is much wear on the input shaft narrow end (where the input shaft rests in the pilot bearing) but I want to make sure.
Does anyone know what the OD of the narrow end of the input shaft is?
I have cleaned it up and there are no grooves or nicks but if it is out and something needs to be replaced I would prefer to do it now.
Also I have gone through the forum and ordered some parts which I will list, am I missing anything else?
Rear Main Seal (looks like it has been weeping a little as the rear of the block is black with oil and clutch dust)
Pilot bearing and seal
Throw-out bearing
New clutch and flywheel w/counter weight (ACT)
Transmission input seal
Transmission output seal
Pinion seal (got a bit of a gear oil shower taking the driveshaft off)
Axle seals (figured if the diff is out may as well change them)
SS clutch line
Check the through bolts on the engine for correct torque.
Should I pull the rear stationary gear and change the o-ring? reading through the forums it seems like the o-ring does not fail very often so why take the risk?
Thanks all
I don’t have the OD for the input shaft. But if you don’t come up with it maybe just slide the new pilot bearing over it? There’s likely going to be a little play/room. The bearing is just there to support. I’d think the biggest issue is being smooth and round.
Profile says you have a 93. With the new PP you MIGHT consider a new clutch fork. I think the early ones were known to fatigue and fail occasionally. Don’t recall details but later versions were supposedly improved.
With the transmission dropped it’d be an opportune time for a shifter rebuild, or at least check that lower nylon bushing.
After doing all that work, I would suggest replacing the rear stationary gear o-ring too. You should remove the rear stationary gear to replace the oil seal. After all, you don't want to damage the e-shaft in the process. If you bought a clutch kit, you will get a clutch disk alignment tool with that kit. The diameter of the tip of that tool is the same as the tip of the input shaft. Here's a photo of the tool: https://www.atkinsrotary.com/89-92-T...ool-PT005.html
Ahh good call Hot Dog, I managed to get a chance to work on the car today and the input shaft feels smooth with no notches or grooves, there is a slight burr but nothing emery cloth won't remedy.
Sgtblue I am going to tear the fork apart and check it over, I have a new clutch SS hose coming from Chris @ Banzai, so there may be more force on the fork with the line not swelling. Do the forks just fail or is there any warning signs?
One thing I noticed today while cleaning the trans is the input shaft has some play, nothing axial just radial play. I was thinking I might change the bearing to be safe but the FSM is saying I need to have an SST between 4th gear synchro and the main drive synchro so that might be a pain without the tool. I will read through the forum and see if there is anyone who has changed this bearing.
Nvm on the play, first thread I read through has a vid saying that is normal. I don't think mine even moves as much and the blueprinted one (you commented on that thread too Sgtblue lol)
As I recall the forks just fatigue near the roll-pin.Nothing visual to warn you and not REAL common. I was just throwing it out as you have a 93 and putting a new pressure plate in. I’m not sure how pricey they are but it would suck to have to drop the transmission again that after all the other stuff. Your call.
Ahh good call Hot Dog, I managed to get a chance to work on the car today and the input shaft feels smooth with no notches or grooves, there is a slight burr but nothing emery cloth won't remedy.
Sgtblue I am going to tear the fork apart and check it over, I have a new clutch SS hose coming from Chris @ Banzai, so there may be more force on the fork with the line not swelling. Do the forks just fail or is there any warning signs?
One thing I noticed today while cleaning the trans is the input shaft has some play, nothing axial just radial play. I was thinking I might change the bearing to be safe but the FSM is saying I need to have an SST between 4th gear synchro and the main drive synchro so that might be a pain without the tool. I will read through the forum and see if there is anyone who has changed this bearing.
The input shaft bearing is a sealed bearing. So, it doesn't rely on lubrication from the gear oil. From my experience, most of them have some degree of play. As long as the input shaft rotates smoothly, I would think it will be okay. Some folks on this forum have managed to replace them without disassembling the transmission. I've never attempted removing this bearing without disassembling the transmission, but I suppose it's possible with either a long jaw gear puller or the SST. How many miles do you have on the transmission?
Atkins is offering a beefed up version of the FD TO bearing fork. It's Atkins' own design. I'm not sure if it's available yet, but here's a photo from their website: https://www.atkinsrotary.com/93-95-R...5-16-520B.html
Mazda beefed up the fork for later years so as long as you get a new one it should be ok. It's not expensive so I usually change it at every clutch change.
The input shaft bearing is a sealed bearing. So, it doesn't rely on lubrication from the gear oil. ….
Maybe I misunderstood or maybe there’s more than one, but the shop that replaced my noisy input shaft bearing said this was it. Just an unremarkable, unsealed roller bearing that would depend on 75w-90.
New fork ordered from Mazda, can't go wrong for $130CAD. I looked at Atkins but at the moment they only have the OE fork, the billet one is not available yet.
@Hot_Dog I would guess this is the original trans, so ~100,000k, looks like it has been apart in the past as the gear box and extension housing joints have gasket goop oozing out and the pan joint has the same messy sealant application.
After reading around sounds like I am going to be doing the input bearing too as there is a good chance that is part of the noise, it never ends... lmao
I would guess this is the original trans, so ~100,000k, looks like it has been apart in the past as the gear box and extension housing joints have gasket goop oozing out and the pan joint has the same messy sealant application.
Mazda used a light gray sealant at the factory, so these transmissions all have silicon at all of the joints.
its light gray though, so if yours is like orange or something then its been apart
Mine is light grey but the application is poor, like on the sides of the transmission not in the joint looks like someone had some on their fingers and got it everywhere lol. Doesn't look like something that would have came from the factory.
Maybe I misunderstood or maybe there’s more than one, but the shop that replaced my noisy input shaft bearing said this was it. Just an unremarkable, unsealed roller bearing that would depend on 75w-90.
The input shaft uses two bearings. I was referring to the front input shaft bearing as shown here: https://www.atkinsrotary.com/89-95-r...1-17-295a.html This bearing is located under the front cover. The roller bearing that you show is used where the rear of the input shaft mates to the front of the main shaft. It's located at the rear or gear end of the input shaft as shown here: https://www.atkinsrotary.com/Transmi...t-y611-17-21x- That bearing is lubricated with gear oil. That bearing is in pretty sad shape. Looks like maybe it was starved of lubrication.
It was definitely toast but never starved…at least while I’ve owned the car. I change gear oil about every 25k, usually Redline or NEO. It had about a 100k on it at the time. Not sure why it went, and neither did the shop. Figuring I’d just let it go until the end of driving season and deal with it over the winter, I damn near let it go too long as it was just starting to gall the shaft. I’ve tried warning others against making that mistake. It looks a bit worse now than when it came out, as it’s been hanging on a peg-board hook for a number of years near a utility sink at my shop to remind me.
this thread is a total cluster , not sure how a group can take such a simple topic and twist it around so badly. As stated in the first post, the needle support bearing is called a pilot bearing, not an input shaft bearing. I can provide the dimensions if you really need them, but typically installing a new pilot bearing suffices. It’s not really critical, just keeps the input shaft pilot end from having excessive deflection.
but you’re kind of screwed with the front input shaft cover being NLA. They wear out too. Not sure what Mazda is thinking by not having that available.
and you need the correct tool for installing the pilot bearing. Which closely mimics the input shaft pilot end, and would also be more appropriate for measurement. The clutch disc alignment tool tends to not be as precision of a fit compared to the insertion tool. Which is also more appropriate for installing the pilot bearing seal as well
The other thing is you need to be careful of tapping in a pilot bearing/seal on an assembled engine. Because the big flat end-play needle bearing is at the front of the e-shaft and you don’t want to damage it or create dents in the running surfaces. If there’s any way to apply pressure on the e-shaft to tension it off the end-play needle bearing stack back towards the rear while tapping in the pilot bushing, it would be best. The biggest chance to cause damage is the pilot bearing being fully seated at the back of the e-shaft bore, but continuing to keep beating it in. So you need to monitor that carefully.
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Thanks for the heads up, I will be very careful with the all the bearings I am changing but will take extra care with the pilot. OEM parts should be here tomorrow or Friday with the clutch arriving next week sometime.
Going to feel like a different car lol, pretty sure the old clutch was slipping a little bit all the time with how bad the flywheel looked and the wear on it.
04-26-24, 11:39 AM
, not sure how a group can take such a simple topic and twist it around so badly. As stated in the first post, the needle support bearing is called a pilot bearing, not an input shaft bearing. I can provide the dimensions if you really need them, but typically installing a new pilot bearing suffices. It’s not really critical, just keeps the input shaft pilot end from having excessive deflection.
