Too Much Power - Not Enough Chassis

[somesnapper]

I have a 95 E36 - with just an intake/exhaust and stock suspension.

Recently had the car inspected and they didnt find any bushings that needed replacing besides the guibo.

The car seems too powerful for its chassis.

The front of the car lifts/dives a bit too much under partial throttle acceleration/braking.

When I push the clutch pedal in - i hear a clunk sound every time in the back of the car. This happens at very slow (parking) speeds. I'm not sure if this is related.

What can I do to help with this? It feels like im hurting the car... :) thanks

[savage217]

is your suspension shot? Sounds like it. The stock power is not even close to being too powerful. Check your subframe bushings, if it feels like the car slides in corners they are probably gone. But I would def go over the dampers first.

[95s52]

When I push the clutch pedal in - i hear a clunk sound every time in the back of the car. This happens at very slow (parking) speeds. I'm not sure if this is related.


the "clunk" sound youre hearing is probably the famous diffy bolt letting you know that its about to, or already has broken. If I where you I would get under the car ASAP, and check it out.

[HBpredhunter]

LOL. your funny bro. grab a bently and do some repairs.

[Foxtrot121]

the "clunk" sound youre hearing is probably the famous diffy bolt letting you know that its about to, or already has broken. If I where you I would get under the car ASAP, and check it out.

Awe shitttt... my car does that some times too...:eek:

[Nik1703]

this car is underpowered, man. the euro version has nearly 100 more hp with the same chassis :shifty

[RRSperry]

Check the diff bolt, for the clunk. If that isn't the problem, check sway bar links.

You didn't say what mileage your car has, but at 13 years the original shocks and struts are probably done, especially with the symptoms you describe. My supercharged 95 has 300+ rwhp and doesn't do that... I have H&R OE Sport springs and Koni dampers.

[Bene36m3]

Ohhh man, mine makes the clunk when i go in reverse...

[Hova]

Ohhh man, mine makes the clunk when i go in reverse...


re-tighten front diff bolt to 71lb of tourque. (per bently). (take it out, then put it back in, and tighten)

[RRSperry]

And use locktite...

[somesnapper]

Thanks guys.

Its on original springs and shocks were changed around 65k.

The car has 115k miles.

I'm not saying the chassis isnt weak... just my particular car has some probs :)

I have a bently - does anyone have a easy way to locate diff bolt?

[1quick4dr]

front of the differential by the input flange

[swollix]

hmm more like too much chassis (weight) not enough power.

[raysadude]

we're not underpowered, i call it balanced :D

[Braymond141]

Clunk can equal many more things than just Diff... come on guys.

Possible suspects: Guibo, diff bolt, rtabs, broken rear shock mount, broken rear shock tower

My vote is, whatever idiot looked at your car has no clue what they're doing. I'd wager your shocks/struts are dead, rtabs shot, and RSMs shot.

[RRSperry]

If the shocks were replaced with OE (Sachs or Boge) at 65 and you have 40K+ miles on them, they are probably toast now too.

Here is a more complete list of what I would check.

Diff bolt. Look at the diff in the carrier from the front looking to the rear. There is 1 bolt 1/2 up, in the front. All you will see is the bolt head. That is the diff bolt. Check that it is tight.

If that is fine, check the Guibo , center support bearing, and drive shaft for play and noise.

Check the RSM's and the rtab's

On your 95 check that the LSD unit is still bolted into the diff. Yea, that's ones a lot tougher, but 95's 3.15 diff is known for having the bolts back out. There was a run of difffs that didn't have locktite applied to those bolts. The bolts can back out and cause all sorts of noise and damage.

[Bene36m3]

re-tighten front diff bolt to 71lb of tourque. (per bently). (take it out, then put it back in, and tighten)

Thanks, will do.

[RRSperry]

Don't forget the locktite.

[Crazy 13immer]

Take it easy Dom.

It had so much torque the chassis twisted coming off the line

[Hova]

Take it easy Dom.

It had so much torque the chassis twisted coming off the line

theres no way there should be that much body flex stock on these cars. Mine has ~140k on it, major bushings are all addressed, as well as shocks, and it feels rock solid. one of the ONLY parts i would recommend putting on a m3 would be a x-brace though. Ive driven one with one (mine currently doesnt have one), and it is a noticable difference when you start to firm up the suspension components.

[Crazy 13immer]

theres no way there should be that much body flex stock on these cars. Mine has ~140k on it, major bushings are all addressed, as well as shocks, and it feels rock solid. one of the ONLY parts i would recommend putting on a m3 would be a x-brace though. Ive driven one with one (mine currently doesnt have one), and it is a noticable difference when you start to firm up the suspension components.

I was just kidding, it was a F&F quote... I wanted to put a picture of Dom, but I'm at work and can't really do it.

I have an X-brace on my car and I've done most of the suspension on my car and have no problems like the OP. My car is pretty solid, although I need to get around to doing the fcabs and such.

[ModBargains]

Sounds like suspension is shot already, especially for a 95, I'm pretty sure its a suspension issue at that point. There isn't a better time to go with coilovers and upgrade over those stock blown shocks BMW calls suspension. We carry many different lines of coilovers, for your application, I would suggest Suspension Techniques coilovers, these are made by KW and of course have life-time warranty.

[somesnapper]

thoughts? thanks

[somesnapper]

How should I go about upgrading suspension?

Should I keep the oe springs and get new struts?

[jiggynites]

forget about shocks and springs for now
your problems is not there. read some of the post above
bmw's have more bushing than you can possibly imagine.
I have replaced 16 bushings on my suspension in less than 2 months
and still have a few to go...... so take your car to a different mechanic
heres my list and you might try to replace these
front sway bar linksx2
front sway bar bushingsx2
rear shock mountsx2
rear trailing arm bushing x2
rear sway bar mounts x2
tranny mounts x2
motor mounts x2
rear exhaust bushing x2

other very important bushings
check rear chassis for broken mounting points
(very comon on e36/e46 for the rear chassis to tear apart)
rear chassis mounts
rear chassis re enforcement mounts
differential mounts
gilbo (flex disc)
control arm bushings
front shock mounts
rear diff bolt

If I were you I start with the rear diff bolt, then rear shocks mounts,
then check rear chassis for cracks and keep going from there

[Hova]

forget about shocks and springs for now
your problems is not there. read some of the post above
bmw's have more bushing than you can possibly imagine.
I have replaced 16 bushings on my suspension in less than 2 months
and still have a few to go...... so take your car to a different mechanic
heres my list and you might try to replace these
front sway bar linksx2
front sway bar bushingsx2
rear shock mountsx2
rear trailing arm bushing x2
rear sway bar mounts x2
tranny mounts x2
motor mounts x2
rear exhaust bushing x2



Front control arm bushings x4
Diff bushings x3
Subframe bushings x4


theres more, but those are the major ones.

[themadhatter]

re-tighten front diff bolt to 71lb of tourque. (per bently). (take it out, then put it back in, and tighten)
pull it out before anything to make sure that it's not bent. they are about $2 max from the dealer.

[Hova]

pull it out before anything to make sure that it's not bent. they are about $2 max from the dealer.

+1


Ive broken one before :D

it is an AMAZING EXPERIENCE...:shifty


i was thinking of another way to reinforce this bolt, why not drill out the threads on the diff (just a little bit), and put in a slightly thicker bolt, with a washer and a nut on the other end? You could go SAE or metric on that, and use whatever grade you think would work (id rather have a bolt bend then break, but if it is just straight through, i dont think it would matter, piece of cake to replace).

[themadhatter]

+1


Ive broken one before :D

it is an AMAZING EXPERIENCE...:shifty


i was thinking of another way to reinforce this bolt, why not drill out the threads on the diff (just a little bit), and put in a slightly thicker bolt, with a washer and a nut on the other end? You could go SAE or metric on that, and use whatever grade you think would work (id rather have a bolt bend then break, but if it is just straight through, i dont think it would matter, piece of cake to replace).
send a PM to Mike Radowski, he has the solution to all of your needs.

http://forums.bimmerforums.com/forum/showthread.php?t=499460

[RRSperry]

Wow, you guys are all over the place. Let's kiss... (keep it simple stupid!)

If you can't or don't know how to do stuff yourself, find a competent mechanic in your area. It isn't hard. Check the local subforum, ask on Suzy''s E36M3 list (http://www.bmw-m.net/), check out the SCCA, BMWCCA... There are tons of people that know the E36 inside and out...

Check the diff bolt. It easy to check, and will cause a clunk. If that isn't the culprit, move on to the next possibility.

As for the chassis flex, get an x brace if you don't have one. It's easy to tell, look under the car, is there a big x shaped hunk of metal tubes under the oil pan? If so, you have one. It is the single best suspension improvement you can do, and it's cheap (about $130).

As for bushings, well, I've owned and worked on E36's M3's since I got mine in 1995, so I do have some background. The only time I've seen bad bushings, the cars had a ton of miles, 100K+, or they had been slammed, or they have had the shocks set too stiff for the spring rates on the car.

BMW did a great job designing and calibrating the M3 suspension. (for what it is...) It is a street car that had to meet the daily driving expectations of a really wide range of people. It had to be compliant, quiet, not twitchy, not jarring, had to last a reasonably long time, in conditions all over the world, and keep it affordable. Given the design constraints, I think they did a heck of a job. Is it perfect? For my wife it probably is. Could it be better? Of course it could. But better at what, and what aspect are you going to trade for. Everything is a compromise, there is no free lunch...

You can't have a race car that is comfy on the street, and you can't have a comfy car work really well in the track. Nobody has figured out how to do that one yet. (they are getting close... Corvette Z06 and ZR1)

Anyway, B4 you go all crazy, unless you race for a living, and your name is Auberlien, or Shumie, the stock M3 is way better than you are. That's probably true for 90% of the M3 owners out there. It's limits are really very high, and it is very forgiving of a lot of stupid mistakes. The more you modify it, the less margin for error you have. What used to be a twitch, with tire squeal, and a slight drift, is now a full spin, and there is nothing your limited skill can do to catch it.


Anyway, I'll get off my soapbox now. The clunk is probably the diff bolt or the LSD unit in the diff.

Get the Guibo replaced, it sucks when they fail.

Go for rides or drive different cars with different suspensions, so you can have an idea of what does what...

Flame suit on....

[somesnapper]

Thanks guys.

FIY .. The guibo and control arm bushings were recently replaced.

I'll try and find a mechanic in your link.

Thanks

[tEckniks]

240hp is insanely powerful. i was at the redline in 3rd and my laptop started going crazy saying danger to engine manifold. :dunno:

[The Letter M]

Wow, you guys are all over the place. Let's kiss... (keep it simple stupid!)

If you can't or don't know how to do stuff yourself, find a competent mechanic in your area. It isn't hard. Check the local subforum, ask on Suzy''s E36M3 list (http://www.bmw-m.net/), check out the SCCA, BMWCCA... There are tons of people that know the E36 inside and out...

Check the diff bolt. It easy to check, and will cause a clunk. If that isn't the culprit, move on to the next possibility.

As for the chassis flex, get an x brace if you don't have one. It's easy to tell, look under the car, is there a big x shaped hunk of metal tubes under the oil pan? If so, you have one. It is the single best suspension improvement you can do, and it's cheap (about $130).

As for bushings, well, I've owned and worked on E36's M3's since I got mine in 1995, so I do have some background. The only time I've seen bad bushings, the cars had a ton of miles, 100K+, or they had been slammed, or they have had the shocks set too stiff for the spring rates on the car.

BMW did a great job designing and calibrating the M3 suspension. (for what it is...) It is a street car that had to meet the daily driving expectations of a really wide range of people. It had to be compliant, quiet, not twitchy, not jarring, had to last a reasonably long time, in conditions all over the world, and keep it affordable. Given the design constraints, I think they did a heck of a job. Is it perfect? For my wife it probably is. Could it be better? Of course it could. But better at what, and what aspect are you going to trade for. Everything is a compromise, there is no free lunch...

You can't have a race car that is comfy on the street, and you can't have a comfy car work really well in the track. Nobody has figured out how to do that one yet. (they are getting close... Corvette Z06 and ZR1)

Anyway, B4 you go all crazy, unless you race for a living, and your name is Auberlien, or Shumie, the stock M3 is way better than you are. That's probably true for 90% of the M3 owners out there. It's limits are really very high, and it is very forgiving of a lot of stupid mistakes. The more you modify it, the less margin for error you have. What used to be a twitch, with tire squeal, and a slight drift, is now a full spin, and there is nothing your limited skill can do to catch it.


Anyway, I'll get off my soapbox now. The clunk is probably the diff bolt or the LSD unit in the diff.

Get the Guibo replaced, it sucks when they fail.

Go for rides or drive different cars with different suspensions, so you can have an idea of what does what...

Flame suit on....

Flame suit? No Way!

This is one of the most sensible posts I've seen in any forum, and I hope you go & post it in every forum out there.

I could not have said it better myself.

Everyone who is mod crazy, please re-read his post until it sinks in.

Kudos for the reality check.

[somesnapper]

What would be the next thing to tackle?

The GUIBO was replaced.