Whiny S4C

I have had some transmission issues in the last couple years and just want to get some input. While my car was down I had all of the worn synchros and shift sleeves replaced and at the same time we did diff bearings and the bearings on either end of the main shaft and countershaft. The transmission whined pretty bad before we did any of that work and we assumed it was the diff bearings. We replaced those with OEM and it got quieter, but was still present. Now that I've put a few hundred miles on the "rebuilt" transmission the whining is louder than it was before the new diff bearingswere installed. It does it in every gear, but loudest in 1st and gets quieter as you work your way up through the gears. I do remember there being a good amount of metal built up on the magnet when we first opened the case and I wasn't sure if that was debris from the bad bearings we replaced or gear material. It has the stock 2000SI open diff in it.

I am leaning towards it being the gears in the diff itself, but wanted to see what people thought or had any tips on how to troubleshoot it before I start ordering expensive parts.

Could always try molyslip or something before you strip it down, not a long term solution if its got serious problems but it generally shuts them up for a while if its just worn rather than failing.

Did you replace the pilot bearing on your flywheel at the same time? This gets often overlooked and if it is badly worn it will allow for the input shaft bearing to fail prematurely. Does the noise change between acceleration and deceleration?

I'm getting all bearings done on my box at the moment. I replaced the pilot bearing on the flywheel as the old one was noisy and loose. I got a koyo bearing from japserviceparts for about 12 quid delivered. I had a. Build up of filings on my magnet and chunks of diff from the old diff as the apparent gearbox specialists done a thorough cleaning and inspection of the box

ColbyCol said:

Could always try molyslip or something before you strip it down, not a long term solution if its got serious problems but it generally shuts them up for a while if its just worn rather than failing.

Click to expand...

I've tried a few different gearbox oils and nothing works to quiet it down.

oifovo said:

Did you replace the pilot bearing on your flywheel at the same time? This gets often overlooked and if it is badly worn it will allow for the input shaft bearing to fail prematurely. Does the noise change between acceleration and deceleration?

Click to expand...

It's an OE flywheel with a new pilot bearing (maybe 500 miles on it) and when the clutch is in or the car is not in gear it doesn't make the noise. It's very loud under load during acceleration and a little quieter on deceleration, but still makes noise.

ruprecht said:

I'm getting all bearings done on my box at the moment. I replaced the pilot bearing on the flywheel as the old one was noisy and loose. I got a koyo bearing from japserviceparts for about 12 quid delivered. I had a. Build up of filings on my magnet and chunks of diff from the old diff as the apparent gearbox specialists done a thorough cleaning and inspection of the box

Click to expand...

All my bearings are new except for the needle bearings inside of the gears. We've never seen those fail before, so leaning towards those NOT being the culprit.

If the noise changes between acceleration and deceleration then that would point to one of the main bearings being gone again. No oil will help with the noise here as the problem is the distance between the input shaft and countershaft will not be within spec if one of the main bearings (usually the input shaft bearing) is shot. You will have to pull the gearbox again I'm afraid.

oifovo said:

If the noise changes between acceleration and deceleration then that would point to one of the main bearings being gone again. No oil will help with the noise here as the problem is the distance between the input shaft and countershaft will not be within spec if one of the main bearings (usually the input shaft bearing) is shot. You will have to pull the gearbox again I'm afraid.

Click to expand...

The transmission has maybe 200 miles on it since we did all new bearings and it was making that noise before we replaced the bearings also. We pulled the case apart a couple months ago and none of the bearings had any drag or play to them. It has to be something else.... I know I'll have to pull the transmission out again, just don't know what parts to order and we couldn't see anything wrong with any of the gears the last time we had it apart.

OK, so the fact the noise is there all the time but gets quieter when going through gears points to something that's common to all gears. This rules out the little roller bearings you haven't replaced as they only work with certain gears IIRC. Is the gearbox shimmed correctly? I've rebuilt a couple of Honda gearboxes and admittedly never even checked the clearance, I just always used the same shim that was in the box but it is something that could cause the issue. TBH if it is just a standard box with an open diff I'd bin it and get a different gearbox. Good excuse to upgrade to a LSD box If you want to save this box I'd say get a new diff and check it is shimmed properly (not that easy to do I don't think, I've never done it)

A new LSD transmission here is $2500 USD without shipping as only the 97-01 Integra Type R came with them and probably 75% of those cars were stolen. That makes legal used transmissions with the VIN still in place almost impossible to find. I'm already $1,200 in to this gearbox because I did all new carbon synchros, shift sleeves, GSR 5th gear, all new bearings, new axle seals, bead blasted the case etc. etc. etc. I doubt my friend who is the transmission guru checked the shimming and who knows if a previous owner threw it together without the proper clearances. I think I'm going to buy an MFactory LSD that's made for my open diff gearbox and go from there. I'll have him check to make sure the clearances are correct this time. Thanks for talking that out with me, much appreciated.

Wow, I didn't realize it was so expensive (and difficult) to get a box in the US! A second hand EK9 LSD box is only around $400 in the UK, non-LSD boxes cost absolute peanuts, I even got one for free, never used it and passed it on for free again! Let us know how you get on, I'm curious to know what the issue is.

oifovo said:

Wow, I didn't realize it was so expensive (and difficult) to get a box in the US! A second hand EK9 LSD box is only around $400 in the UK, non-LSD boxes cost absolute peanuts, I even got one for free, never used it and passed it on for free again! Let us know how you get on, I'm curious to know what the issue is.

Click to expand...

I paid $300 for the one I have now and it basically needed new everything. It was the only one I could find that had a vin tag still attached and wasn't stolen. That was about 6 years ago, so now it's even worse. The only options are to buy stolen ones and live with the fact that you have stolen parts or pay over $2k for a new or refurbished transmission. I think I've only heard of one person with an EK9 LSD box locally and he sold the car years ago. I'll get it figured out eventually and make sure I post pictures and updates here.