Auto to manual swap grinding noise

[notporgu]

Hey everyone, first time posting here but I've hit a metaphorical pothole. I finally got everything together and when I went to start it up, it sounded a lot harsher than it did before the swap.

Here's the information I have so far:
My car is a 1988 325i convertible, originally auto.
I swapped in a Getrag 260 with a RHD flywheel, and a sachs clutch kit.
The grinding noise is only when turning over, after startup it's fine. I think I am seeing flecks of metal getting tossed around, but it could just be loose debris flying from vibration.
I opened up under the trans and looked inside while starting, and it looks like the starter is engaging past the flywheel, but I don't know for sure what it's supposed to look like.

From what I gather online, 325i's all came with single mass flywheels, so the starter should be compatible with the flywheel I bought from RHD, but again I don't know for sure.

Any and all advice will really help on this, as I really don't want to screw something up.


Side note, while investigating this issue, I saw a video where someone mentioned you need to install the flywheel with the shim (part #11221710038) to spread the load of the bolts, but I don't think I installed that. Do I need to take things apart and put in that shim? And will I be able to reuse the bolts?

[82eye]

Hey everyone, first time posting here but I've hit a metaphorical pothole. I finally got everything together and when I went to start it up, it sounded a lot harsher than it did before the swap.

Here's the information I have so far:
My car is a 1988 325i convertible, originally auto.
I swapped in a Getrag 260 with a RHD flywheel, and a sachs clutch kit.
The grinding noise is only when turning over, after startup it's fine. I think I am seeing flecks of metal getting tossed around, but it could just be loose debris flying from vibration.
I opened up under the trans and looked inside while starting, and it looks like the starter is engaging past the flywheel, but I don't know for sure what it's supposed to look like.

From what I gather online, 325i's all came with single mass flywheels, so the starter should be compatible with the flywheel I bought from RHD, but again I don't know for sure.

Any and all advice will really help on this, as I really don't want to screw something up.


Side note, while investigating this issue, I saw a video where someone mentioned you need to install the flywheel with the shim (part #11221710038) to spread the load of the bolts, but I don't think I installed that. Do I need to take things apart and put in that shim? And will I be able to reuse the bolts?

any progress on the issue ?

i'm about to install a new rhd flywheel and bosch starter, so have a vested interest. it does seem like something is up with the starter. the flywheel gear is generally supposed to be harder material than the starter gear, if there is an issue between the two it'll be the starter that takes it.

the shim should probably have been installed. i don't think it is causing the start issue as it installs on the opposing side. replacing flywheel bolts is a recommend any time the bolts / flywheel are removed. in practice i know shops that do clutch replacements don't always replace them. i'm guilty of this myself on other cars, but i would advise against re-using them.

[notporgu]

I currently have the transmission out and am installing the shim, and the previous bolts are not long enough with it plus the rhd flywheel. It may be that the bolts I bought are "automatic" but I was under the impression that they should be the same.


This is them fully loose. Kinda sketch.
I don't like reusing them but I have no choice really.

As for the starter, it looks like it's just really finicky. It has a lot of play when it's loose and is sort of adjustable.

I'll get everything back together and update again.

[notporgu]

Update: everything is back together, after several attempts at adjusting the starter, no dice on getting it to stop grinding. As for the bolts and the shim, I had a tech look at it from the shop I work at, and he said he wouldn't trust that few threads, so I omitted the shim after all. Hours of work down the drain UGH. Anyway, I've narrowed it down to a few options. Here's the order in which I believe to be most to least likely

1st, the battery is dead, causing the starter to operate improperly. I know for a fact the battery is crap, but I'm not 100% on it causing the starter issue, but I think I remember reading somewhere that the battery can cause grinding.

2nd, the RHD flywheel is ever so slightly larger in diameter compared to the original flex plate. I lined up the flex plate and flywheel outside the car when I first installed it, and the teeth lined up 1 for 1. However, it's very possible that to total diameter of the RHD flywheel is maybe a millimeter or so larger than the original, causing the starter to over engage with the teeth. My thinking for this comes from this picture I took after painting the teeth and running the starter.


You can see the paint is worn off down into about 5/6ths of the tooth, when it should be down only around 3/4th or 2/3rds.

The third and final option I've considered (and please Lord let it not be this) is the trans I bought was in some sort of accident, and the bellhousing is bent ever so slightly, causing poor engagement.

I'm going to start with the battery for now, since it needs replacing anyway. If it doesn't help I'm just going to run it for a week or two and hope the issue resolves itself, otherwise I'll have to park it for a few months since I'll be out of town and I need at least somewhat reliable transportation lol.

[notporgu]

Update: new battery, same issue. At this point it's beyond me for what the issue could be. If anyone has any advice I'd greatly appreciate it.

[82eye]

Update: new battery, same issue. At this point it's beyond me for what the issue could be. If anyone has any advice I'd greatly appreciate it.

hmmm. generally a start up grind issue is - battery / starter / flywheel, from cheapest to expensive. if not battery then the next cheapest is starter issues - discounting the fact you've replaced the flywheel for the moment.


starter is where 90% of stuff happens or breaks.
if it is starter, then it can be : improper alignment, worn or stripped gear, solenoid failure, and plain wore out. first and quickest cheap fix is double check the install. which i'm sure you've done. next expensive short cut to eliminate issues is a new starter. if you pull it to replace the solenoid, you might as well replace it.


if you check where the grinding is coming from i'm sure you're gonna find it's the starter. a sheer guess would be the new flywheel just would play better with one. talk to your mechanic.the old one doesn't look all that bad. i would have replaced it as a given on a trans swap though, regardless of the flywheel.

on the flywheel - i would reach out to rhd and perhaps inform them you may have encountered a quality issue. if the flywheel is indeed out of spec it would prove kinda onerous to them.

[82eye]

forgot to mention, that is one thick ass shim. maybe because from auto ? mine's like a few ml

good catch not to use it then. the rhd flywheel shouldn't require it considering the material. just re-use the bolts.

[notporgu]

first and quickest cheap fix is double check the install. which i'm sure you've done. next expensive short cut to eliminate issues is a new starter. if you pull it to replace the solenoid, you might as well replace it.

I've done both already. First started with replacing actually, then adjusting the new one, to no avail. I had to test it just by cranking without fully turning over, since I had things ripped apart at the time and didn't want to cook my engine bay. Even with the new starter and several attempts to adjust it, it was still producing the same grinding sound. I don't really know that there's a lot of room to adjust it though, since the bellhousing dust shield has that hole that the starter fits into. Though I didn't test the new starter with the new battery, but I don't think it should matter. I swapped the old one back in since it was perfectly fine before the swap, and I don't want to kill a brand new starter during this diagnostic period.

talk to your mechanic.the old one doesn't look all that bad. i would have replaced it as a given on a trans swap though, regardless of the flywheel.

I talked to a few people around the shop, and all I could gather is that something isn't right lol. I was able to determine though that the starter seems to be over engaging like I showed in post 4.

on the flywheel - i would reach out to rhd and perhaps inform them you may have encountered a quality issue. if the flywheel is indeed out of spec it would prove kinda onerous to them.

I actually thought about this too, I looked on their site to verify the size of the flywheel is the same, and they have it listed at 30x30x6cm, but my flex plate is at ~29.3cm in diameter. It could be that they're rounding, or it could be that they have an extra 7mm of diameter and that's what's chewing up my starter. I would measure the one I have, but it's currently installed in the car and I really don't have time to pull my trans again. So instead I contacted them through their support page and am waiting to hear back.

[82eye]

I actually thought about this too, I looked on their site to verify the size of the flywheel is the same, and they have it listed at 30x30x6cm, but my flex plate is at ~29.3cm in diameter. It could be that they're rounding, or it could be that they have an extra 7mm of diameter and that's what's chewing up my starter. I would measure the one I have, but it's currently installed in the car and I really don't have time to pull my trans again. So instead I contacted them through their support page and am waiting to hear back.

considering i have one coming my way i just might double up that with you.

edit : don't wanna run them down, maybe throw thread link to them for reference. they're a popular choice. it'd be nice to see a happy resolution.

[notporgu]

considering i have one coming my way i just might double up that with you.

edit : don't wanna run them down, maybe throw thread link to them for reference. they're a popular choice. it'd be nice to see a happy resolution.

Once they respond if they have any questions I'll point them here. I don't doubt they make a high quality part in the slightest, in fact driving with it is great so far, minus the engine trying to stall out whenever I pull it out of gear lol. Though I suspect that's due to the ECU still learning the new normal, or some other kind of issue at idle. I'm just trying to eliminate possible culprits to my grinding issue. I'll update once I hear back from them, though it might not be 'til Monday, it being the weekend and all.

[notporgu]

Update: heard back from RHD and they basically told me to check to make sure I have the locating dowels and the dust shield installed, which I do, and to verify my flex plate has 137 teeth, which it does. Not much more they could say really with the info I gave them, but after pouring over the media I've gathered, I think I may have found exactly what is grinding, if not why.

I took footage of starting way back when I first finished, which I've uploaded here. Using this I determined the direction the starter rotates to narrow down which side of teeth are actually getting worn, to better understand the picture I've already posted. Below I've drawn up what I believe is going on.


Ok maybe I'm going a little crazy but hear me out. So the blue arrow is the rotational direction as determined by the above video linked. The link highlight therfore indicates the faces of the teeth being engaged. If you look at red line, you can see that's right up against the curvature of the inside edge of the pinion gear. Basically where it stops becoming an actual gear. You can also see on the right edge of that same bottom tooth, the paint isn't fully stripped off! There's a distinctive line where it cuts off. I think what's happening here is the starter engages too far, smashes into the flywheel, and grinds up against the curved inside edge of the pinion gear. Your can see evidence of this in the cyan circle.

Now why is this happening? Not a dang clue. All I can say is it looks like it's a sixteenth of an inch or so too deep. Not sure how to fix that, or why it's happening. I'm going to respond to the email I got from RHD and give them what info I can, including this page. (Hello RHD support if you're reading this!)

If anyone else has ideas, still open to ideas.

[82eye]

U

Now why is this happening? Not a dang clue. All I can say is it looks like it's a sixteenth of an inch or so too deep. Not sure how to fix that, or why it's happening. I'm going to respond to the email I got from RHD and give them what info I can, including this page. (Hello RHD support if you're reading this!)

If anyone else has ideas, still open to ideas.

did you source the trans swap all from the same vehicle or did you piece it together ? there is a difference in bell housing depth on some g260's. it changes by about 3/4 of an inch, as an outside guess it may be related to your issue.

[notporgu]

did you source the trans swap all from the same vehicle or did you piece it together ? there is a difference in bell housing depth on some g260's. it changes by about 3/4 of an inch, as an outside guess it may be related to your issue.

The ebay listing I bought was written up as a 325i trans, but he could have been guessing.

Though, the depth of the bellhousing shouldn't change the depth of the starter engaging with the flywheel. The whole bellhousing is flat up against the motor either way.

[Panici]

I currently have the transmission out and am installing the shim, and the previous bolts are not long enough with it plus the rhd flywheel. It may be that the bolts I bought are "automatic" but I was under the impression that they should be the same.

The shim is different between automatic and manual. See the below picture from my manual swap. Automatic shim is thicker.

All I can say is it looks like it's a sixteenth of an inch or so too deep. Not sure how to fix that, or why it's happening.
If anyone else has ideas, still open to ideas.

Shim the starter out a sixteenth of an inch?

[snafubmx234]

Now why is this happening? Not a dang clue. All I can say is it looks like it's a sixteenth of an inch or so too deep. Not sure how to fix that, or why it's happening. I'm going to respond to the email I got from RHD and give them what info I can, including this page. (Hello RHD support if you're reading this!)

If anyone else has ideas, still open to ideas.

I'm dealing with this exact same issue. I purchased the RHD "single mass" flywheel and have the same Sachs clutch that you do. I did so under the pretense that DMF and SMF all used the same starter, mostly because folks said they did the swap and didn't change their starter. One thing I'm finding out is that most 325i in the US had a dual mass flywheel... or at least that's my hypothesis, and there is a gear tooth spacing issue based.

I purchases their SMF HERE, and am using a "stock rebuild" for my 88' 325i, and have the exact same grinding as you. Same discoloration and marks on the teeth as you. As listed on their website, and after speaking with RHD yesterday on the phone, it appears we should have procured the DMF version HERE to use our typical starters. The kind gentlemen on the phone recommended to try and early model starter. I have a '84 325E starter on the way, and I will take measurement of the teeth between my two starters, and the flywheel. If there is a difference, I'll do the math/CAD to help visualize it.

Good luck, and I'll keep ya posted later this week.

Colin