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qazwsx

Straight cut gears for E36

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I've bought 1996 323i with a gearbox whine that the owner claims is due to having straight cut gears installed. He seems like a very genuine person and I'm inclined to give him the benefit of the doubt, but is this even remotely possible? While googling will bring up the famous video of that racing e36 with the sequential box, nothing seems to suggest there are any such kits to put straight cuts into the regular e36 box.

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Is it possible?

http://rdtransmissions.co.uk/Category/63/getrag.aspx
https://store.vacmotorsports.com/samsonas---dog-ring-gear-m50--s50-family-zf-transmission-p2698.aspx
https://shop.quaife.co.uk/bmw-six-speed-heavy-duty-sequential-gearbox
http://www.hackengineering.co.uk/product/samsonas-45-speed-dog-gear-set-zf-s5d-gearbox/
http://www.rwracing.nl/bmw/

Anything is possible with the right amount of money thrown at it. Is it likely? Well there's the real question.

Can you confirm the whine is not from the diff or somewhere else? Is there any paperwork to back up this claim? Have you checked it's not a bearing in the box that is failing? Is it just straight cut gears or a dogbox? Any way of checking the box itself, such as draining the fluid and visually looking at the gears?

I'm only asking this because the cost of straight cut gear sets here in NZ is horrendous, so unless it is some top competition car, or the previous owner got lucky buying a different box, the expense would most likely rule out anyone forking out thousands of $$ for a special gearbox for a daily driver. Whilst I am hoping you have struck the jackpot and found a straight cut box, I am thinking statistically the likelihood of this happening is slim to none.

Would definitely be interested to know for sure if it has one.

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If I was going to spend big money on a straight cut gear set, I would not be putting them in a 323i. Just my 2 cents.

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Are you sure they weren't genuinely delusional? I can't for the life of me see why you put a fancy box in a 323i, (320i maybe, for class reasons) and if they happened to have one sitting around surely they'd have a bigger engine to put it behind.

I also shouldn't have clicked on those links... Straight cut gears for my spare 265 would be interesting.

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Think i was looking at that car also, said his "friend" installed the parts and now overseas and not contactable. Also remember it having B30 internals? Again done by a "friend"

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This isn't the red E36 coupe is it?

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Well that makes it impossible then. Since it's not a dog leg.

3 hours ago, Lucan said:

This isn't the red E36 coupe is it?

Yup that's the one. Was there a post here about it?

Are you sure they weren't genuinely delusional? I can't for the life of me see why you put a fancy box in a 323i, (320i maybe, for class reasons) and if they happened to have one sitting around surely they'd have a bigger engine to put it behind.

I also shouldn't have clicked on those links... Straight cut gears for my spare 265 would be interesting.

Not that it makes a lot more sense, but it does have a stroked M52B28.

Edited by qazwsx

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oh the b30

5 hours ago, HaNs said:

Think i was looking at that car also, said his "friend" installed the parts and now overseas and not contactable. Also remember it having B30 internals? Again done by a "friend"

Sorry but you have definitely been scammed

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1 hour ago, qazwsx said:

Well that makes it impossible then. Since it's not a dog leg.

Yup that's the one. Was there a post here about it?

Not that it makes a lot more sense, but it does have a stroked M52B28.

Ah, you missed out the part about the M52B28 (Stroked to B30?).

Also dogbox =/= dogleg.

 

Dogleg refers to the shifter arrangement with 2-3 being straight up and down.

Dogbox refers to the internal construction of the gears, and lack of synchros if memory serves.

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2 hours ago, thorburn said:

oh the b30

Sorry but you have definitely been scammed

Well I'm confused. It mostly isn't bullshit. The lsd, m3 brakes, headers, lightened flywheel, are all there. I can't confirm that the engine is a B30 hybrid with forged pistons, but it's a lot faster than a B25. Straight cut gears just seems like such a ridiculous thing to lie about. Then again, shame on me for missing something so obvious. Hope I don't have to go through the disputes tribunal, but the seller isn't dodging me or anything.

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Just have a look through the gearbox drain plug at the gears. Youll soon see

 

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2 hours ago, qazwsx said:

Well I'm confused. It mostly isn't bullshit. The lsd, m3 brakes, headers, lightened flywheel, are all there. I can't confirm that the engine is a B30 hybrid with forged pistons, but it's a lot faster than a B25. Straight cut gears just seems like such a ridiculous thing to lie about. Then again, shame on me for missing something so obvious. Hope I don't have to go through the disputes tribunal, but the seller isn't dodging me or anything.

There's a big difference between a bog-standard 323i (which is what we thought you had) and a 323i with a b30 and those mods. Now straight cut gears doesn't seem so ludicrously far-fetched.

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15 hours ago, polley said:

Just have a look through the gearbox drain plug at the gears. Youll soon see

 

+1 to this.

That car is reputedly quite well put together. 

It would be very unusual to run straight cut gears though as they have extremely strong gear sets in the ZF (pretty sure it was a zf box) 

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20 hours ago, polley said:

Just have a look through the gearbox drain plug at the gears. Youll soon see

 

Yeah we've put a camera up there and we see some helical gears There's one straight one which is probably reverse. Fluid was also low and dark.

Another unusual thing the seller said was that 1, 2, 3, and 4 were straight cut while 5th was helical. Finally, a straight cut wouldn't whine while idling in neutral even with the clutch out, would it?

Seller has said he will try and contact the friend who supplied it to him.

Anyway case closed, thanks for chiming everybody.

4 hours ago, dirtydoogle said:

+1 to this.

That car is reputedly quite well put together. 

It would be very unusual to run straight cut gears though as they have extremely strong gear sets in the ZF (pretty sure it was a zf box) 

Do you know of the car somehow?

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1 hour ago, qazwsx said:

Finally, a straight cut wouldn't whine while idling in neutral even with the clutch out, would it?

No, it wouldn't. So the whine is coming from somewhere else, just a matter of finding out where now so you can fix it. Fingers crossed it isn't something bad causing the whine. If it's doing it in neutral while idling I'd suspect something driven by the belts causing it - most likely culprit is probably power steering pump low on fluid or on it's way out.

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4 hours ago, Mad_Max said:

No, it wouldn't. So the whine is coming from somewhere else, just a matter of finding out where now so you can fix it. Fingers crossed it isn't something bad causing the whine. If it's doing it in neutral while idling I'd suspect something driven by the belts causing it - most likely culprit is probably power steering pump low on fluid or on it's way out.

It's definitely from the gearbox, it also stops with the clutch pedal in. Mechanic who says he's seen this lots have said it's the input shaft bearing.

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1 hour ago, qazwsx said:

Mechanic who says he's seen this lots have said it's the input shaft bearing.

Input shaft bearings don't whine like an unpaid hooker when they are gone, they rattle badly but only when in neutral, foot off the clutch and engine idling. The rattle goes away once you hit the clutch pedal and are moving. That's just my experience, ex mechanic and having blown up several input shaft bearings says to me the whine is coming from somewhere else.

I have no idea where you are, I'm in the deep south. If you're anywhere near me I'm more than happy to have a look at it for you and give a second opinion.

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Interesting.

I'm all the way up in Auckland, but thanks for the offer.

 

Now the question is, and putting aside the straight cut gears completely, given that the car was advertised as having a recently reconditioned gearbox but turned out to be not (oil was black and low) and has some sort of bearing problem, what is a fair compensation I should ask from the seller? I will go down a few notches from there since I want to believe him that he was unaware of his friend's bamboozling.

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A replacement box is probably fair if you can install it yourself.

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Sounds dodgy, straight cut gears are usually installed on reverse, first and second sometimes third to handle the torque of a high output engine; but they only whine when being driven in that gear  they don't whine in neutral or when stationary and are not affected by clutch position. 

The links do show full straight cut sets- question is what casing do you have?

More likely a toasted gearbox courtesy of a grunted up engine and possibly even an undersized gearbox 

Edited by 3pedals

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