The tunnel insulation is rubbing on the drive shaft

[Quicksilver328i]

I was talking to someone with an 850 and he said he took his insulation out because it was going the same thing, but he replaced iut with a piece of dynamat to keep the noise/heat down. It actually made the car a fair bit quieter and doesn't hang down anymore. He just cleaned the area thoroughly and glues the dynamat up there. I imagine a couple simple metal brackets bent to shape and clipped at the bottom (of bent back to the tranny support) would hold it up and out of the way. It falls away from the point where the shifter support bar slides in on my car.

No paint for 8-10 inches - ignore it, figure it keeps rust away and if I fix it I'll have rust (I'm just lazy).

[Tanks95]

How much heat will it let in if removed? I'm assuming its not really going to do any harm removing it, but how much extra heat are you feeling in the cabin?

When I installed my UUC Clutch I cut every bit of that crap out. However, I can’t really speak of the amount of heat because I don’t drive it that much. You can hear the tranny more with the insulation removed, which doesn’t bother me but it may bother some.

[M52 POWER!]

The insulation is more for sound than heat. I haven't noticed any extra heat or sound though.


Plus its a race car now (tranny insulation removal mod) +15whp!

[Theodore]

In that case, F-it. Out it comes! Like the dynamat idea though.

[Tanks95]

In that case, F-it. Out it comes! Like the dynamat idea though.

yup, makes it easier to get to the top tranny bolts and the shift linkage also.

[bennyfizzle]

just cut mine out w00t, my car doesn't sound like a 1991 caprics anymore

[BRMiller]

I used a couple self tapping screws and a 1” wide strip of thin sheet metal.

I threaded the sheet metal up and over the shift linkage and then pressed it into the contours of the tunnel. Made a couple marks where the metal was at the peak of the tunnel, then pulled it out to pre-drill the screws into the sheet. The insulation is now well braced and quite secure!

Here are a couple pics:

https://imgur.com/gallery/uXpbUNj

[DrftKingIII]

I used a couple self tapping screws and a 1” wide strip of thin sheet metal.

I threaded the sheet metal up and over the shift linkage and then pressed it into the contours of the tunnel. Made a couple marks where the metal was at the peak of the tunnel, then pulled it out to pre-drill the screws into the sheet. The insulation is now well braced and quite secure!

A lovely update to a 13 year old thread.

[BRMiller]

A lovely update to a 13 year old thread.

Ha! Thanks, dude, that’s funny

And it’ll be relevant 13 years from now too! 😀

[JitteryJoe]

Ha! Thanks, dude, that’s funny

And it’ll be relevant 13 years from now too! 

True enough. It is a well known and much discussed problem. One of the forum members (Brett) sells a bracket to solve this problem.
https://www.msportparts.com/collections/brackets-and-reinforcement-plates/products/e36-transmission-tunnel-insulation-brackets

Not cheap but specialty one-off parts typically are not. And it fixes the problem.

[Hova]

True enough. It is a well known and much discussed problem. One of the forum members (Brett) sells a bracket to solve this problem.
https://www.msportparts.com/collections/brackets-and-reinforcement-plates/products/e36-transmission-tunnel-insulation-brackets

Not cheap but specialty one-off parts typically are not. And it fixes the problem.

Was going to suggest this. Worth every penny. They are by FAR the best fix for this. (outside of redoing the entire insulation).

[shogun]

Unfortunately the set Brett sells is applicable to manual transmission only.

[JitteryJoe]

Both my M's had this problem. I actually looked at buying new trans tunnel insulation but it is expensive. Needless to say sissors did the trick. I cut mine out right in front of the shifter. On a side note one of my M's shift way better because the crap was rubbing on it too.

New tunnel insulation includes attached firewall insulation. It is a big job as you have to strip the firewall to do it right. There is a lot of stuff attached to the firewall. I did this but only because the engine was already out. It was still a huge PITA.

[Braymond141]

Shogun,

Automatic don’t have this issue as bad because the alu heatshield is longer helping retain the insulation shape.

Technically they do work, but I removed the compatibility from my list because I made a mistake in how easy they are to install. I just didn’t want to deal with it. Manual owners take a few minutes, autos take an hour+.

- - - Updated - - -

Thank you Joe and Hova for the support

To those thinking about cutting the insulation; Yes, it’s cheap and works... however it looks really tacky and the insulation inside falls out for ages after you break the seal.

[shogun]

Yes, I had that wobble also on my automatic M3, but not that bad, insulation was falling down at the rear of the 5HP18 and onto the giubo, 4 years ago I just cut the insulation in that area and the rest still holds. But on the long run I will give the insulation some support. As I have a pit and a transmission jack, it made it easier to do the job. Exhaust must come off. So we loosened the 6 copper nuts M10 in the front (have 6 new of them ready) , but did not take them off the bolts, so the exhaust was secured in the front but movable downwards, rear and middle we took off the brackets/rubbers and with the trans jack we lowered the exhaust so far, that we could pull out the silver color metal shroud between exhaust and driveshaft towards the rear, the wires from the O2 sensors were long enough, so even no need to disconnected the O2 sensors.
The 'fiber' mat was already damaged from the giubo and the fibers came down, so no chance to fix it somehow. So I used a cutter knife and scissors and cut all from the old fiber mat from the end of the trans housing - above giubo - driveshaft off, so all of that mat above/around the giubo and driveshaft is gone now, no more noise. No need to cut much, maybe around 10-15cm width.

But your solution is excellent.

[NeilM]

I took a length or hardware store perforated steel strip, bent it into an inverted U, and positioned it looped over the transmission to support the original sagging insulation mat. There are a couple of existing weld studs with plastic nuts on either side of the tunnel that I used to attach the U — no additional fasteners needed. Cheap, effective and has been working well since 2005 — before this ancient thread started!

I was installing a clutch/flywheel at the time and had the transmission completely removed, but it should be doable without that.

In an ideal world I'd cut out the transmission tunnel part of the insulation but leave the firewall section in place, then use Koolmat #04248 or similar (https://www.koolmat.com/heat-resista...ts-protection/) to line the tunnel. However in an ideal world I'm never taking my transmission out again!

Neil

[TostitoBandito]

I used 3M spray adhesive to stiffen up and restore the integrity of mine (sprayed between the delaminating layers), and also to stick it to the underbody. Seems to still be holding up ok. If it ever starts to sag again I'll just buy those brackets.