:dude:hi ,can anyone tell me why my car , an automatic, jerks when i put her in drive, both in forward and reverse , is it the gearbox or drive gear ,its the same hot or cold, also there's a noise coming from the front which i have been told is coming from the alternator, any one else had this problem? Paul
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It could be a combination of poorly set up tick over via the throtle cable and the kickdown cable may need adjustment.
Stuart
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There's always a bit of a jerk when an old automatic takes up drive, usually down to slight wear in the driveshafts, propshaft etc. etc. It is made much worse if your tickover speed is set too high, from memory I think it's supposed to be around 700rpm.
Noise from the alternator is a bit more tricky. If it's not a worn alternator, it's worth checking the pully fan, as it's quite tight for space and can and up contacting other components causing a noise and/or bent blades.
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:dude: hi stuart, I had the car tuned about two months ago, It seems to tick over fine , the jurking was there before the tune up. could it be the u-joints taking time to take up the drive?, If i put it in 1st then up to drive It not to bad. paulComment
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Hi Paul
The kickdown cableis unlikely to have anyreal effect onbumpy engagement of gear unless it isVERY badly out of adjustment- if that was the case I'm sure you would have mentioned the gearchange speeds being very high as well.
What you haven't said is if there is a significant delay between moving the selector to the D or R position and you feeling the gear engage with the jerk/bump - also is there any form of "Clang" or similar mechanical noise revealing a large backlash in the propshaft/diff/driveshafts.
If there is a delay and no mechanical noise, you could well have a failing front pump in the transmission and the overall 'box pressure is down. A pressure test of the gearbox would tell that straight away.
You also don't say if there is a significant difference in behaviour in the general gearbox when cold and hot - this can be useful to know when diagnosing auto faults.......
Russ
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Hi Paul,
Do you have your foot on the footbrake when you select a gear?
Ray
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Got enough fluid in the box? Had a similar problem and found the fluid level low. Topped up and all ok.Comment
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:dude:hi guys, I do use my foot brake when engaging the gears, there is a clunking noise when slotting the gearsforwards or reverse, there is no differences hot or cold, who do I get to check the pressure?, and do I have to check the oil when it is hot?, and do I have to move the gear stick up and down before I check the oil level?. PaulComment
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Hi mate
Check the oil hot, go through all gear selector postions with engine running and back to park, and dip with the engine running at idle.
Gearbox pressure could be checked by any competent garage with the correct adaptor, a 150psi (preferably 250 psi) oil pressure gauge and a rev counter, or by yourself if you can get hold of the kit.
I'm sorry but I won't lend my kitout as it's been with me for 30 years, but if you ever passed through Surrey way I would be happy tocheck it for you - if the pressure test plug comes out OK (if some animal hasn't butchered the Allen socket plug on the BW65) it only takes 30 mins to check the pressure and adjust the downshift cable.
You should check with a friend where the clunk is from - If you can borrow a pit or a 4 poster ramp then that would be ideal, but otherwise jack the rear of the car, put it on axle stands, and then go underneath to watch what happens when the car is run through the gear selector positions.
Russ
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:dude:hi kryten, thanks for the ifo, I will check the oil first, then the noise, then go on from there. paulComment
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