Cartorious

In need of Diagnosis, Transmission problems?

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Obligatory apology if this is the wrong location to post asking for help, also if this description is too "vague" etc...

I have what I believe to be a transmissiom problem with my Daily Driver '75 02. Inside is a 5-speed manual transmission swapped in a long time ago from another BMW (I believe it is the ususal one that is used for these kinds of swaps)

As soon as the clutch is quarter engaged (as I am enetering a gear, shifting UP), the clutch seems to Fully Engage, and send the car into an "overdrive" mode (Car accelerates quicker than usual).

Interesting things to note:

- This only happens in 1st or 2nd gear

- As soon as I stop accelerating, the car ends overdrive mode, lurches forward and performs as normal (with a violent shake that rattles the whole car).

- If I am careful to let out the clutch EXTREMELY SLOWLY, the problem Rarely occurs

-The shaking is so violent it actually tore through the upper radiator hose on one incident

-Shifting DOWN into either gear (remember, only happens on 1st and 2nd) The problem does not occur.

I honestly have no idea what is going on with my car. This has been a problem for 1 month as of now, am afraid to take it in because of possoble high cost to repair.

THANK YOU

-Carter

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When you say overdrive do you mean that the engine revs up? Could this be your clutch slipping?

Pull your handbrake up hard, put the car in 2nd and try and drive off. Do you get the same 'overdrive'?

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I'd advise that someone on this board that lives in the area, offer to test drive the car to diagnose the issue.  It's either that or it's time to take the car to a mechanic.

 

Unless you are willing to hoist the car and take pictures of the transmission etc you'll only get a lot of conjecture from people here.

 

Anyone near Wilsonville. :)

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Are your motor mounts and transmission mount good, not broken? I only say this because of your comment regarding the torn radiator hose, which makes me wonder if your engine is not exactly where it should be with respect to the chassis, the pedal box.

Regards,

Steve

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Are your motor mounts and transmission mount good, not broken? I only say this because of your comment regarding the torn radiator hose, which makes me wonder if your engine is not exactly where it should be with respect to the chassis, the pedal box.

Regards,

Steve

+10.

Motor mount. Not Just the rubber parts, but the subframe split on the drivers side.

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your motor mount

 

They beat me to it.  Since they are both better looking, quicker off the line, AND smarter...

 

Open the hood, set the parking brake hard, and slowly let the clutch out.  Your engine will climb up and out of the bay. 

While the hood's open, look for the telltale shiny spots on its underside.  Where the air cleaner's been smacking it.

 

It's the driver's side mount, most likely.  Do a REALLY hard launch and you'll break your distributor cap...

 

t

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... Do a REALLY hard launch and you'll break your distributor cap...

 

t

Uhhh, maybe you should hold off on that REALLY hard launch...

Regards,

Steve

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When you say overdrive do you mean that the engine revs up? Could this be your clutch slipping?

Pull your handbrake up hard, put the car in 2nd and try and drive off. Do you get the same 'overdrive'?

This is interesting that you say that... I remember that around the time thid started happening I tightened the nuts on the E-Brake cords A LOT. Could that be what's causing this?

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Nope. I was asking you to put the brake on hard to see if we could get your clutch to slip. I am liking the engine mounting suggestion now.

Stand on the right hand side of the engine compartment and push and pull the top of the engine as hard as you can while looking at the engine mounting at the centre-bottom of the block and see what you can see. You might need to take the stock air filter off to get a good look.

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If you haven't replaced your three motor mounts in the last four or five years -- well, two motor mounts and one transmission mount --just buy new ones and change them. Then re-assess your transmission shifting issue.

Marshall's (mlytle's) emphasis is to make certain that, in addition to the driver's side mount, you've examined and, if needed, repaired, a crack that routine routinely appears in the subframe bracket for that mount. Search Forum on strings such as "motor mount crack" for discussion of this topic.

Regards,

Steve

,

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If you haven't replaced your three motor mounts in the last four or five years -- well, two motor mounts and one transmission mount --just buy new ones and change them. Then re-assess your transmission shifting issue.

Marshall's (mlytle's) emphasis is to make certain that, in addition to the driver's side mount, you've examined and, if needed, repaired, a crack that routine routinely appears in the subframe bracket for that mount. Search Forum on strings such as "motor mount crack" for discussion of this topic.

Regards,

Steve

,

Understood... I had a mechanic look at it very briefly an hour ago who suspected the motor mounts needed replacing as the engine was able to be rocked back and forth by him when the car was off (I guess this is a bad thing).

 

I'll order new rubber mounts as soon as next payday and use the 4x4 ratchet method to lift the engine and install them myself. I will look for the subframe crack tomorrow.

 

Thank you everyone for the help.

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