22 replies to this topic

[jetmechinnc]

Finally got my car up and running after resto started back in November, mainly just structure stuff, nothing done to engine/trans really, now more trouble shooting. It's a 1978 Mini 1000 4 speed R/H drive.  Would like a suggestion to what to look at or for. I have a bad rattle/vibration in the front of the car. Not sure if it's the CV joint, drive shafts, transmission, all the above. Basically in fourth gear say 60 mph, at level road, I get a bad rattle noise/vibration that can shake the doors. Doesn't seem to do it 1st gear thru 3rd though. At least not bad. Plus, the vibration/rattle goes away immediately if you let off the gas peddle while on the highway so I dont' think its an unbalanced wheel. It also goes away if you are turning sharply to the left or right or loading up the engine like going up a steep high while pressing the gas peddle.

Second question, when you shift gears, it clunks/jars the car if you don't ease into gear with the clutch. I've changed out the upper and lower engine brace bushings and it seems that the previous owner has changed the engine mount near the radiator. Is there another mount to look for that could be broke/worn/missing? Something from the shifter to the engine?

Thank you

 

Jason

[xrocketengineer]

Differential about to go?

[Guess-Works.com]

Possibly, Lift a wheel and with it in gear turn the 'free wheel' to see how much free play or lash is in the differential, Anything more than from 12 o'clock to 2 o'clock suspect a worn diff pin.

 

However, I'm more inclined to suspect a driveshaft issue, or moreover, inner CV (pot joint) issue... best way to check is get under the car and grab a hand full of driveshaft and give it a good shake up and down, and see what moves...

[jetmechinnc]

Possibly, Lift a wheel and with it in gear turn the 'free wheel' to see how much free play or lash is in the differential, Anything more than from 12 o'clock to 2 o'clock suspect a worn diff pin.

 

However, I'm more inclined to suspect a driveshaft issue, or moreover, inner CV (pot joint) issue... best way to check is get under the car and grab a hand full of driveshaft and give it a good shake up and down, and see what moves...

Ok great starting point for me.  I'll be checking these items during my weekend starting Tuesday.  Guess I'll have to see in my Haynes book about how bad it is to change the diff pin or inner cv pot joint if need be or would I have to result in a shop to do my work if special tools are required. 

 

Any idea about the clunking when shifting?  Is there a mount somewhere for the shift linkage I need to see if still there?

[Guess-Works.com]

Changing the diff pin is basically an engine out job, there's a few on here which will 'claim' it can be done with the engine in the car, but IMO, it's quicker to take the engine out. The clunking when shifting may also be connected with the diff pin, as the lash is taken up, but I would also investigate engine mounts and also the 2 cotton reel mounts connecting the gear shift to the floor.

[jetmechinnc]

Changing the diff pin is basically an engine out job, there's a few on here which will 'claim' it can be done with the engine in the car, but IMO, it's quicker to take the engine out. The clunking when shifting may also be connected with the diff pin, as the lash is taken up, but I would also investigate engine mounts and also the 2 cotton reel mounts connecting the gear shift to the floor.

 

As far as the cotton reel mounts, where would they be located?  Are they listed in the Haynes manual or mini spares catalog?  I've so far changed out the bushings on the upper engine brace, the lower engine brace on R/H side.  I believe the former owner changed out the engine mount by the radiator simply because I seen new AN bolts there from the wheel well

[Guess-Works.com]

cotton reels mounted behind the gearstick under the floor ( lift the carpet and you'll see the studs ) and support the mechanism... if these are worn firstly you get a really wooly gear change, but can also knock against the body by the movement of the engine.

[jetmechinnc]

cotton reels mounted behind the gearstick under the floor ( lift the carpet and you'll see the studs ) and support the mechanism... if these are worn firstly you get a really wooly gear change, but can also knock against the body by the movement of the engine.

 

Thank you for the input.  If I get home by nightfall from work I'll check out the cotton reel mounts and drive shafts.  Should the drive shafts be able to move in any such manner as in and out or should they be fixed?  I think I remember them being able to slide in and out when I changed the rubber cones/shocks.  I'd assume they shouldn't move up and down. 

[jetmechinnc]

I guess, the worst case, would it be just worth saving up money and ordering a reconditioned gearbox from guess works?

[xrocketengineer]

I guess, the worst case, would it be just worth saving up money and ordering a reconditioned gearbox from guess works?

That is what I did. It was cheaper to buy it right out from him than trying the exchange route with MIniMania or the others since mine damaged the diff casing. Mine had the pot joints moving in and out just before it 'sploded and did this:

Edited by xrocketengineer, 28 July 2014 - 12:50 AM.

[jetmechinnc]

 

I guess, the worst case, would it be just worth saving up money and ordering a reconditioned gearbox from guess works?

That is what I did. It was cheaper to buy it right out from him than trying the exchange route with MIniMania or the others since mine damaged the diff casing. Mine had the pot joints moving in and out just before it 'sploded and did this:

 

 

 

This is something I don't want to have happen, especially on a road trip to Myrtle Beach to see my folks and show them my new toy!  Gotta track down this vibration culprit now!

[jetmechinnc]

In reference to the pot joints, or inner cv joints, should they be able to move in and out at all?  If they do, is that most likely a missing lock ring?  or worse?  I haven't had the time yet to fully check them out besides noting alot of oil/grease around the rubber.  Should the drive shafts be able to move in and out as well or should they be firm in place betweeen the inner and outer CV joints?

 

Thank you for all of the help so far.

[xrocketengineer]

Like I said, mine (at least the left one)  were moving in and out about 1/4 inch. This was in addition to the clunking on acceleration/deceleration.

[jetmechinnc]

Ok, lifting the car up, and with the car in gear, the front wheels free spin only about from 12 o'clock to 1-2 o'clock.  So by the suggestions, I'd say the differential pin is OK, anyone disagree?  Now, the R/H pot joint/inner CV joint is sticking out about 1/4 inch from the transmission case and has a good bit of oil on it.  The L/H pot joint is near flush with the transmission.  The Hanes book does not say per how flush they need to be but am I correct in assuming this is incorrect and it needs to be replaced?  I can't physically move the pot joints in and out nor the drive shafts.  Unless maybe I get a hammer or something.  Any suggestions would be great.  Thank you

[jetmechinnc]

Also, is there something in the transmission that holds them in or is it the pot joint itself with a locking feature.  The Hanes book states you can change this joint with the engine in the car, but if the transmission needs something to make this joint stay in place, will I have to pull the engine?