240 General: Low-Pitched Whine At Slow Speeds

[Othen]

Originally Posted by TheHungriestBadger

ATF is all nice and red these days, it's had plenty of drain-refill cycles at this point. Regarding why I don't want to do this stuff myself is that this is my only car, and I need it to work for a while yet. Spending £100 or so on labour seems like a good deal to have a car that still works afterwards 😂

I also don't have access to a driveway at the moment because I'm still a student, so it's uni car park instead, which is fine, just a little annoying since the pressure is still there to have it moved again by Monday. I'm also pretty physically weak as well - I'm used to contorting my hands into shapes an octopus would be jealous of for electronics work, but muscling things into alignment is not my forté.

It depends how easy the engine mounts are I guess. I'll watch Involvod's video on it again, and see if I'm feeling up to it. Some final questions for now:

1) Which side would you recommend I start with, right or left?
2) How much support do the engine/transmission need? I seem to remember hearing a ratchet strap around the engine is sufficient, but does the trans need supporting by a jack as well while doing this?

... in your circumstances I'd say the garage would be best.

[TheHungriestBadger]

I thought as much 😂 if it wasn't my only transport, it'd be a different matter perhaps. Ah well, thanks all for the help nonetheless, I'll keep this space posted on any outcomes.

[TheHungriestBadger]

Can I just ask, what kind of damage can occur if one does jack up the transmission too much, apart from the (seemingly) obvious of cracking the ATF cooler lines and dipstick tube, which I've already convinced myself I haven't managed.

[Othen]

Originally Posted by TheHungriestBadger

Can I just ask, what kind of damage can occur if one does jack up the transmission too much, apart from the (seemingly) obvious of cracking the ATF cooler lines and dipstick tube, which I've already convinced myself I haven't managed.

It is sort of unlikely that you have damaged anything important by jacking up the transmission too far, as long as the two engine mounts have not actually sheared through so the drivetrain was unsupported. Is there any particular reason you are suspicious that you would like to expose?

[TheHungriestBadger]

No, the motor mounts are still in one piece so far as I can tell - certainly, the car still drives as smoothly as it did (which was fairly smooth, except for a rumble on deceleration which I lived with since no extra noises over 6k miles).

My only suspicion that I may have done, is that I needed to jack it up quite far (i.e. more than just 1", but probably not more than 3") to force the cross-member back. It seems pretty obvious that something shifted more towards the rear of the car in the process, otherwise it would've all just lined back up again pretty nicely.

My curiosity comes from seeing lots of people say "don't do it or else big damage" but don't state along what kind of lines that big damage is. 'tis all

[Bob 1967]

I had the exact same issue, I tried to replace the GB mount, not realising the engine mounts had gone. I struggled to get it back together until I replaced all the engine mounts.
The sheer weight of the engine may have shifted when the gearbox mount was released. Even if the mounts were good.

[Bob 1967]

Other thing, was the driveline assembled when the gearbox was raised.
Could the drive plate/flange(from gearbox), joining to the propshaft have kinked/bent? (probably not, as it would vibrate like a spin cycle on a full load)
Or damaged a bearing by putting a stress against it's axis?
I know I'm giving more questions than answers, but it's a process of elimination.

[TheHungriestBadger]

The engine mount under the oil filter looked somewhat swollen, and the one on the opposite side looked like it was starting to crack/perish on the outer surface (similar condition to the trans mount I took off), so presumably the weight has indeed scooted everything out of alignment to the point of something new being unhappy. By the time it gets to the garage, car will have done about 3 miles total, so fingers crossed that a new set of engine mounts (and the correct trans mount) solve all. I'm guessing if they don't then it's either carrier bearing, or something more sinister with the diff (input bearing or pinion/backlash thereof?) or transmission (tailshaft bushing I guess?).

No vibrations, certainly not new ones - being in North Wales at the moment, descending some of the steeper hills has resulted in some fancy massaging seats 😉 but that's about it, braking on the flat or uphill, cruising, or accelerating (aka 99% of the time), the ride is smooth as can be, except at idle where it's a tad shaky - likely just in need of an ignition tune-up.

Again, the only new thing is the whining/whirring noise which is brand new, and was instantly present from the second I drove away after doing the trans mount. I'll try get an audio recording of it on my way to the garage, although hopefully, it'll be no longer by the time I get the car back.

Define "driveline assembled"? Was the cross-member bolted back up tight with the trans still jacked up? Yes, because otherwise the cross-member couldn't be pushed vertically up far enough to thread the bolt through it and into the chassis.

[Bob 1967]

Driveline assembled , the gearbox output connected to the propshaft and all the way to the differential .
So basically 1 piece from engine to diff.

[Bob 1967]

I cut about 10mm of each end of the studs on the gearbox mount, to ease fitment. Space is restricted. Also there was way too much thread on the crossmember side to get a socket on when removing it and I didn't want to go through that on refitting.
I have a different gearbox, but the principles would be quite similar.


Even with the gearbox side stud cut, the was barely room to get a ring spanner
through the gap.