FE-FC Holden Discussion Forum

Technical Board => General Technical => Topic started by: nicko on May 01, 2004, 08:47:41 PM



Title: lock up in reverse
Post by: nicko on May 01, 2004, 08:47:41 PM
finally rebuilt clutch master and slave cylinder on FE today ,, started it up and went to reverse out , moved 2 feet and felt like the brake had come on,stalling car, so i took both back wheels off and adjusted brakes backing them off quite a bit to be sure,then tried again finding the same problem,when i take car forward a foot or so it can roll on its own so i put it in reverse and reved engine and tried again managed to get it slowly moving .it sort of feels like the gearbox or diff is binding up is this possable?
reguards Nick


Title: Re: lock up in reverse
Post by: mcl1959 on May 01, 2004, 11:55:30 PM
Nick, does the car roll backwards without the engine on?
If the car is out of gear and will roll backwards then its not the brakes or diff.
Can you jack the car up and roll the wheels backward by hand?
Take the tailshaft off and start the car up and run the car in reverse.  This will test the gearbox by itself
Ken


Title: Re: lock up in reverse
Post by: nigelb42 on May 05, 2004, 08:32:41 AM
Nicko,

Did you end up sorting this problem? If so what was it - if you don't mind me asking  :)

Nige


Title: Re: lock up in reverse
Post by: nicko on May 05, 2004, 08:53:22 AM
no not yet,have been cleaning yard up so tried rolling car backwards,with box in neutral ,no go, so shoved it in reverse and floored it so engine would stop stalling and left back wheel spun ,only way to get car into backyard was to reverse away into street and then drive it around side of house to back yard . the only way i could get it out was to just spin the left rear wheel ten foot across the grass and another ten foot onto rd so i could get it out,funny thing was when i went and looked to see which wheel was dragging the was no other marks on grass or street so the other 3 wheels must of been turning,but during all this spinning the car only moved back at a snails pace.tomorrow i plan to jack car up and have another look.


Title: Re: lock up in reverse
Post by: ACE on May 05, 2004, 09:17:59 AM
Hi Nicko,
Has the car been sitting for a while?
It sounds to me like you have a problem with the right rear wheel cylinder. ;)
Regards ACE 8)


Title: Re: lock up in reverse
Post by: nicko on May 05, 2004, 09:21:50 AM
not sure how long its been sitting before i got it,but i backed both rear brakes off a fair bit and it goes easy forward but wont push back and i also sanded all brake drums clean of surface rust .


Title: Re: lock up in reverse
Post by: fcee on May 06, 2004, 07:35:47 AM
 I had this happen in an Fe years ago and it turned out to be a pin in the diff which is held in by a circlip which had fell out ,could drive all day forward but only a couple of feet in reverse before locking up ,sounds like the same problem !


Title: Re: lock up in reverse
Post by: nigelb42 on May 06, 2004, 09:07:04 AM
Hiya Nicko

Now I have heard more, Iwould have to agree about it being a final drive related problem.

The symptoms you describe sound to me like the diff pinion gears or the diff side gears.  I am not sure how 'mechanical' you are so if you understand how a final drive works scroll to the last line  ;) If not a final drive (mistakenly called a diff by all and sundry  :) )works as follows:
First of all the main components are the Main pinion (input), the Crown wheel (reduction), the differential carrier and differential gears (allows cornering), and the axles (mongrels of things that break when doing wheelies).

The differential gears are four smaller gears in the very centre of the final drive, two are splined to the axles and known as side pinions and two are attached to the diff carrier by a shaft and are known as diff pinions.  All four of these 'pinions' are in constant mesh.  So in other words drive comes into the final drive from the propshaft and through the main pinion.  The main pinion drives the crown wheel (at a reduction) which is attached to the differential carrier.  Because the two diff pinion gears are attached to the diff carrier as well they turn with it (but they can also rotate freely on the shaft). As the diff pinions are in mesh with the side pinions, these are driven as well and because the side pinions are splined to the axles drive is sent to the rear wheels.
But, if one axle is prevented from driving by some external factor then all the drive will take the easiest path and be transfered to the opposite wheel because the whole setup allows the diff pinions to 'walk' around the side pinions as required during cornering.  

Soooooooo what I guess I was trying to get at is that if one of the side pinions or one axle was being held or it had a dodgy bearing then a lot of the drive would go to the opposite wheel, hence your wheelspin.  The problem you've got is to eliminate all the other external factors like brake shoes on arse about, broken pins or springs and one brake locking on - which you seem to have done.
The only real thing to do is to drop the final drive centre out and have a gecko or perhaps pull that side axle out and check it.  

If you have an FE/FC workshop manual the rear axle section has a very nifty exploded view of the final drive so you can see what I was jawing about.

I hope I have helped in some way - good luck.

Nige


Title: Re: lock up in reverse
Post by: nigelb42 on May 06, 2004, 09:15:59 AM
Sorry, to add to that last novel, why is it only doing it in reverse?  buggered if I know, but final drives are fineky and funny things.  Almost possesed at times.  ;D

nige


Title: Re: lock up in reverse
Post by: nicko on May 06, 2004, 10:07:42 AM
great news,the rh brake cylinder was siezed,i pulled it apart and used 600 grade wet and dry to polish inside and installed new rubber seaal and car reverses fine and brakes work good,
thanks for your help.
reguards Nick


Title: Re: lock up in reverse
Post by: ACE on May 08, 2004, 12:35:46 AM
Hi Nicko,
Thats great news.
I'm glad you sorted out the problem. :)
Regards ACE 8)