machining 750 bushes for e28

[rob101]

hello everyone,

just wondering if anyone knows the site that has the dimensions that you have to machine the 750iL bushes to fit the e28 thrust arms. think i might give it a go, for shits and giggles.:p

[rob101]

bump damn:(

[Anthony (M5 in Calgary)]

bump damn:(

Try www.mye28.com

[genphreak]

Try www.mye28.com (http://www.mye28.com)Heating them up might do it...?

[rob101]

Heating them up might do it...?
lol the diameter difference is in the vicinity of 5 mm i read so yeah have to machine but thats okay, i just remember seeing a site somewhere with the procedure etc. i just can't find it .

[genphreak]

lol the diameter difference is in the vicinity of 5 mm i read so yeah have to machine but thats okay, i just remember seeing a site somewhere with the procedure etc. i just can't find it .I thought that e34 ones fit straight on/were the same, maybe some are different, I don't know. I'll measure the old ones I have tommorrow and advise the diameter for you then. :) Nick

[bfd]

I thought that e34 ones fit straight on/were the same, maybe some are different, I don't know. I'll measure the old ones I have tommorrow and advise the diameter for you then. :) Nick

No, E28 control arms are smaller than E34 and thus the 750i bushings do not fit. There are basically 3 vendors who sell a milled 750i bushing to fit the E28 control arm: Bav Auto ($60 each), Dinan ($50 each) and www.ultimategarage.com ($35 each).

As to milling your own, from the BMW database:

Date: Tue, 28 Mar 2000
From: "Steve D'Gerolamo" <steved3@idt.net>
Subject: [uuc] 750 Thrust Arm Bushings

You don't need to spend a lot of money on these for your E28 or E24 car.
Pick up a pair of fluid filled 750i bushings (the green ones made by Boge)
and take the center down equally on both sides so it fits perfectly in your
subframe. I use a 20hp Leadwell lathe but you can use a few hand tools
around the shop. Now machine a few mm off the steel casing equally on both sides so this will not contact the subframe with side deflection of the
arm.

If your thrust arms are in very good shape except for the bushing, you can
simply replace the bushings...on the car with an OTC7249 or you can
carefully remove the old arms with the proper ball joint press (you dont
want to damage the ball joint side) and 5-10 tons with your shop press and
proper sized arbor.

I personally would rather replace the thrust arms with new Lemforder/oe
components at this time. This way you can use a bit more force and a
separator fork to muscle the old ones out. Pick up a new set of arms from
your favorite parts supplier and press in your newly machined bushings. Be
careful using a shop vice and big socket in lieu of a press and
arbor....you may break the handle off the vice or puncture the bushing
(remember, these are fluid filled) with a poor fitting socket. SD (PS-
these bushings work great in E32/E34 cars without the machining)

[rob101]

there is the other option of those grunt bushes aren't they made by a mob in australia? noltec?

[Anthony (M5 in Calgary)]

[QUOTE=bfd]You don't need to spend a lot of money on these for your E28 or E24 car.
Pick up a pair of fluid filled 750i bushings (the green ones made by Boge)
and take the center down equally on both sides so it fits perfectly in your
subframe. I use a 20hp Leadwell lathe but you can use a few hand tools
around the shop. Now machine a few mm off the steel casing equally on both sides so this will not contact the subframe with side deflection of the
arm.

QUOTE]

Ah, I see. The OD of the bush is correct for the ID of the thrust arm but the bushing itself is too wide to fit in the subframe...

[Bill R.]

narrow it up enough to fit... a mill is more elegant.. most people dont use a lathe on it.. but anything to remove material from the sides will work.. however crude it is.




[quote=bfd]You don't need to spend a lot of money on these for your E28 or E24 car.
Pick up a pair of fluid filled 750i bushings (the green ones made by Boge)
and take the center down equally on both sides so it fits perfectly in your
subframe. I use a 20hp Leadwell lathe but you can use a few hand tools
around the shop. Now machine a few mm off the steel casing equally on both sides so this will not contact the subframe with side deflection of the
arm.

QUOTE]

Ah, I see. The OD of the bush is correct for the ID of the thrust arm but the bushing itself is too wide to fit in the subframe...

[rob101]

narrow it up enough to fit... a mill is more elegant.. most people dont use a lathe on it.. but anything to remove material from the sides will work.. however crude it is.

yeah i'd be lathing, i haven't used one for a while but i think i should be up to it, what kind of fit are the bushings normally?

[bfd]

yeah i'd be lathing, i haven't used one for a while but i think i should be up to it, what kind of fit are the bushings normally?

A local BMW junkyard/repair facility is selling Meyle control arms with 750i bushings on ebay starting at $109/pr:

http://cgi.ebay.com/ebaymotors/NEW-TRICK-BMW-CONTROL-ARMS-E28-528e-535i-M5-M6-635_W0QQcmdZViewItemQQcategoryZ33583QQitemZ8054332 615

The price is right, but is this a good deal? Figure the modified 750i bushings alone would be $40-60 each (Dinan/Bav Auto/ultimategarage). Are Meyle arms anywhere near the quality of Lemforder?

As for "Grunt" bushing, unless you're racing/x-crossing, haven't heard good things about urethane bushings (too noisy, harsh, wear fast).

[calmloki]

For my 533i E28 I bought a Harbour Freight metal cutting bandsaw. It did a tidy job of removing a wafer of metal from each side of each bushing - tapped them into place. Ended up with a "free" tool vs. buying machined 750 bushings. Here's a scary bit of info: the local BMW dealership spreads the metal and forces the 750 bushings into place on E28s - or did, doubt any E28s are spending dealership money these days. It has been suggested that an M5 bushing is a superior option to machined bushings - and a slip fit.
Tom

[Paul in NZ]

It has been suggested that an M5 bushing is a superior option to machined bushings - and a slip fit.


E28 m5?

[BigKriss]

Yes, they are noltec


there is the other option of those grunt bushes aren't they made by a mob in australia? noltec?

[calmloki]

E28 m5?
Yup - supposed to be more properly compliant.

[bfd]

Yup - supposed to be more properly compliant.

Actually, the E28 535i has the same bushing as the E28 M5. The *upgrade* is the 750i bushing, which btw is 56mm wide. The E28 bushing is 50mm wide. From the BMW database, here are some part numbers:

1.) E31, E32, E34 Thrust Arm Bushings (56 mm wide)
- --------------------------------------------------
E32 750i, 740i E31 850i, 840i
31 12 1 136 607 $ 45.75

E34 M5
31 12 2 226 528 $104.75

E34 535i, 540i, 530i
31 12 1 139 456 $ 46.50
31 12 1 136 606 expired 03/91
31 12 1 133 488 expired 12/90
31 12 1 130 587 expired 03/89

E34 525i
31 12 1 136 605 $ 49.83

2.) E24, E28 Thrust Arm Bushings (50 mm wide)
- ----------------------------------------------
E28 M5, 535i (after 9/85), E24 M6, 633i, 635i
31 12 9 058 819 $ 36.43
31 12 1 126 394 expired 11/90

E28 533i, 535i (til 9/85)
31 12 9 058 818 $ 30.98
31 12 1 125 428 expired 01/89
31 12 1 126 302 expired 09/86

E28 528e, 524 TD
31 12 9 058 817 $ 47.28
31 10 1 129 078 expired 11/88

Here is Pete Read's E28 M5 owner's description of what works:

If you look closely, you can usually find the last seven digits of the
part number on the part itself. For example, the 750i/850i bushings
will have "1 136 607" stamped in the green plastic insert which
surrounds the center aluminum piece.

Each of the bushings above should be physically interchangeable
within their group. That is, any of the group #1 bushings will fit
on the E31, E32, and E34 cars, while any group #2 bushing will fit
the E24 and E28 cars without modification.

The bigger engine, heavier cars have the stiffer bushings. So the
stiffest E31, E32, E34 bushing is the 31 12 1 136 607 used on the
750i/850i, while the stiffest standard E28 bushing is the
31 12 9 058 819 used on the M5/M6/535i/635i.

The 31 12 1 136 607 for the 750i/850i is the high performance bushing
of choice for E24/E28 cars, but it must be properly machined to prevent interference. You won't find the part number on modified 750i/850i bushings because the plastic insert with the part number is also machined.

[rob101]

lol all the e28 boys come out the woodwork eventually:D