Birty Dastards Jeep Club

Tech Forum => Workshop => Topic started by: lizardland on November 28, 2006, 06:30:08 PM

Title: Axle Change - Any Tips?
Post by: lizardland on November 28, 2006, 06:30:08 PM
My front diff is knackered and I've managed to get hold of a replacement front axle. Planning the swap for the weekend, does anyone have any tips (98 ZJ)? It looks straightforward which usually means an 18hr job and loads of swearing.

Cheers,

Stuart
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Post by: greggmo on November 28, 2006, 06:40:21 PM
shouldn't be too bad a job. be sure the axle you have bought is the exact replacement with the correct ratio r,n,p ratios.
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Post by: dtooth on November 28, 2006, 07:10:28 PM
seems obvious but disconnect the calipers from the old one and hang them up so you don't have to bleed them.

you will need plenty of axle stands and a pair of trolley jacks to make like easier.
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Post by: Mike Pavelin on November 28, 2006, 08:39:39 PM
It helps to have an assistant, theyre very very heavy. Also, ZGs have eccentric bolts on the lower arms to set the caster angle at the axle end. Make a note of their position on the old axle and refit in the same position on the new one.
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Post by: Dave69 on November 29, 2006, 08:16:36 AM
make sure the jeep is jacked high enough off the ground to give you plenty of room underneath. use axle stands and slide the front wheels under the cahssis rails as well as a secondary safety measure if the axles stands fail for some reason. this will then give you the tyre width of gap and might save you from being crushed

 try and use hex sockets rather than the multi-hex ones. this will save on rounding bolt heads as you undo them.
 wire brush bolt threads if possible to remove all the grit and road grime so to  stop and nuts siezing up
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Post by: eastryjeep on November 29, 2006, 01:57:11 PM
Spray all visible threads with penetrating oil, starting yesterday!
PlusGas is my personal favorite, WD40 works well enough but 3in1 tends to be a bit too thick IMHO.
Take herds of digital fotos as you strip it down, they are priceless if you need to refer to them on reassembly and cost nowt. If you've not got a camera either buy one as this is a good time of the year or use a mobile phone!
Reassemble using new nuts and bolts on all suspension items and use a thread locking compound, Loctite or similar, it keeps things torqued up the way they should be and it keeps moisture out of the threads stopping that dreaded corrosion.
Where possible, assemble with bolts or screws pointing downwards, if the nut falls off things only get loose but stay in place, the other way round and things can get scary.
New disks & pads might be nice if you can afford them, and ensure the brake disks are clean before reassembling the calipers to avoid an embarrasing experience on your test drive!
Wipe all grease and oil off the reassembled parts and give a couple of coats of paint to keep the rot at bay.
Get your wheels aligned at the first opportunity.
Good luck!
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Post by: tim_aka_tim on November 29, 2006, 02:13:53 PM
Quote from: "eastryjeep"
Spray all visible threads with penetrating oil, starting yesterday!
PlusGas is my personal favorite, WD40 works well enough but 3in1 tends to be a bit too thick IMHO.


As a side note, PlusGas is awesome stuff, but if you're struggling to get it and can only get WD-40, then GT-85 would be a much better bet. Buy it at the bicycle section in Halfrauds.
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Post by: barttheguinnessguy on November 29, 2006, 02:51:36 PM
Put a bit of copper slip on all the bolts as you put it all back together. You will thank yourself if you ever need to take it all apart again :wink:
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Post by: Mr.Stu on November 29, 2006, 04:10:32 PM
The trouble with useing copperslip on everything is it means you over-torque all the bolts as the torque settings are for dry bolts and by adding the copperslip you've reduced the friction on the threads.

Stu.
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Post by: Dave69 on November 29, 2006, 07:59:32 PM
if your planning on doing this over a weekend, paint the hard to get areas of the bodywork with uderseal or a chassis enamel as a preventative measure then rebuild the following day
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Post by: barttheguinnessguy on November 29, 2006, 08:16:12 PM
Quote from: "Mr.Stu"
The trouble with useing copperslip on everything is it means you over-torque all the bolts as the torque settings are for dry bolts and by adding the copperslip you've reduced the friction on the threads.

Stu.


I sit corrected :oops:
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Post by: Bubba on November 29, 2006, 10:36:02 PM
crap
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Post by: chrisjones on November 29, 2006, 11:18:22 PM
Quote from: "Mr.Stu"
The trouble with useing copperslip on everything is it means you over-torque all the bolts as the torque settings are for dry bolts and by adding the copperslip you've reduced the friction on the threads.

Stu.


That don't sound right to me.
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Post by: Toastie on November 29, 2006, 11:20:38 PM
Besides loads of beer, two floor jacks are a big help for moving stuff around.

In the US good beer and pizza is a very important part of Jeep mods :drinkers:
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Post by: greggmo on November 29, 2006, 11:48:46 PM
the beer and pizza is a very big part of any good jeepers woekshop. :lol:
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Post by: lizardland on November 29, 2006, 11:49:32 PM
Quote from: "Dave69"
make sure the jeep is jacked high enough off the ground to give you plenty of room underneath. use axle stands and slide the front wheels under the cahssis rails as well as a secondary safety measure if the axles stands fail for some reason. this will then give you the tyre width of gap and might save you from being crushed

 try and use hex sockets rather than the multi-hex ones. this will save on rounding bolt heads as you undo them.
 wire brush bolt threads if possible to remove all the grit and road grime so to  stop and nuts siezing up


Many thanks for all the replies so far. This reply has been something that I've been thinking about already. Are axles stands under the chassis rails good enough for doing the work on? I'm a bit concerned about the stability, are there any other measures (apart from the wheel tip which is something I've always done anyway) to keep everything safe and secure?

Cheers,

Stuart
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Post by: daggie on November 30, 2006, 06:51:52 AM
check that the lower conrtrol arm bolts are NOT seized  in the bushes  :banghead: cos the are a bastard to get out & if they are seized, the bushes in the control arms are fucked :roll:
I ended up making two new bolts :banghead:

copper slip mmmmm  :roll:
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Post by: Dave69 on November 30, 2006, 08:10:46 AM
if your using a torque wrench how can you over torque a bolt ? copper slip or no copper slip the torque will always be the same.


someone prove me wrong !!!
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Post by: Mike Pavelin on November 30, 2006, 09:11:42 AM
By lubricating the threads and the underside of the bolt head and/or washer you are reducing the amount of friction/resistance against the turning force required to turn the bolt. Therefore it requires less force (in this case turning torque) to stretch the bolt to a certain point once it is screwed home. This can lead to thread or bolt failure.
A few years ago Chrysler sent a bulletin round all it's dealerships instructing them to never grease wheel studs and nuts for exactly this reason. Several Chrysler vehicles had broken wheel studs soon after being serviced, and on investigation, although the remaining wheel nuts were torqued correctly the threads had been greased.
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Post by: MK1 on November 30, 2006, 11:57:20 AM
Surely crap studs?

I always grease wheel nuts/studs. I also have an unhealthy liking for copper slip.
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Post by: Dave69 on November 30, 2006, 01:13:23 PM
i always put axle stands under the chassis rails and put the wheels under as well. mainly due to personal safety as i have had axles stands sink into tarmac in the past when working on cars during the summer. i now weld two tie bars in a cross fashion so to limit this is it happens.
 the jeep itself should be stable enough when this is done, if your not happy just put some more supports underneath but not in the way of hampering your work
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Post by: JamesH on November 30, 2006, 05:19:12 PM
I usually cover everything in copperslip, do it all up tight, drive it and a check a few times to make sure. Things like control arms just need doing up really tight - just be careful not to snap the smaller bolts when you've been muscling others  :wink:

P.S. I do use torque settings for certain jobs - I'm not a complete cowboy  :lol:


J
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Post by: greggmo on November 30, 2006, 05:46:50 PM
you torque em up so they don't come undone. its all a lot of faf if ya ask me. the only time a torque wrench has been near my jeep was to do the axle rebuilds. everythin else gets a dose of grease and done up tight. nothin has fallen off yet... :wink:
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Post by: Bubba on November 30, 2006, 07:25:09 PM
so the news of the world is true life :?:
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Post by: Dave69 on November 30, 2006, 08:31:45 PM
i stand corrected.

TBH a spring washer or lockwire is always a security on critical bolts. always copper slipped the front brake caliper bolts on my bike and lockwired them as well.

don't want to knock the yanks but whats the point of having an old book like that in the 21st century when the major automotive builders don't follow their own preachings, (plenty of hands experience to back that statement)
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Post by: Bubba on November 30, 2006, 08:59:01 PM
i see it but i wont believe it its a load of hokum try ya fancy book out on a cj where the bolts have been for twenty years you will be kin glad you did have a tin of copperslip...in fact i rekon i would use that book    as a block under me jack
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Post by: eastryjeep on November 30, 2006, 11:22:30 PM
OK lads I think we should all agree to disagree on what to put on screw threads, other than nuts of course and lets help Lizard out shall we   :?:

From a safety point of view, don't forget to chock the rear wheels, (call me paranoid but I do both sides, front and back), and NEVER work under a vehicle that is just supported by jacks, regardless of type, make or experience - it's just inviting a catastrophe.
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Post by: greggmo on November 30, 2006, 11:48:15 PM
you are right mate. though that was rather good hyjack dont ya think? like they say, what ever you gotta do under yer truck be safe and make  sure it aint gonna land on you. :shock:
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Post by: eastryjeep on December 01, 2006, 12:00:42 AM
That was no hijack, it was bloody theft  :!:
But I enjoyed it just the same!!!
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Post by: JamesH on December 01, 2006, 07:33:47 AM
An interesting tangent I thought!

OK, I did my axles recently and would say you ideally need at least two jacks, 4 axle stands, some ratchet straps and a perfectly level concrete base to work on! Straps help pull things into position and line bolt holes up on re-assembly.

I have an unlevel tarmac drive which made it fun. If working on tarmac put your jacks and axle stand on sheet of plywood/MDF of similar to stop them sinking in. Also stack your wheels and whatever you have that is suitable underneath to support the Jeep if it does wobble off stands.

For the unbolting/bolting make sure you have big enough ratchets/breaker bars. You will also need several sizes of hammer - a good size lump hammer is particularly useful I find, especially on control arm bolts.

I'll leave the WD40 & copperslip decisions up to you  :wink:
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Post by: Dave69 on December 01, 2006, 07:51:39 AM
just give it a good steam clean first
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Post by: trent on December 01, 2006, 11:36:28 PM
Always, safety first!
I find this approach works well :lol:










(http://http://i84.photobucket.com/albums/k8/trentyj/hi-liftneeded.jpg)
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Post by: eastryjeep on December 05, 2006, 12:54:15 PM
Is that 'technician' really welding the fuel tank :?:

Or is that a really big dollop of copper-slip I can see?
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Post by: chrisjones on December 05, 2006, 01:41:08 PM
Nope.  That's a welder, and that's a fuel tank!

....and this is me running away! :D