Rear Axle R&R ...
04-19-2013 | 08:51 PM
#1
Thread Starter
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Joined: Oct 2003
Posts: 7,210
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From: Nova Scotia
Rear Axle R&R ...
An unusually late arrival of spring has kept the toys in hibernation too long - prep'd the 928 last week and started the C4S a couple of days ago .... just the usual: off the battery tender, fire up, change oil & check fluids, etc.
Closing the door on this deal after installing the second oil filter - and noticed an apparent 'line' on the outer right CV boot: rolled the axle, and voila ... a gaping split!
The right rear (RR) axle happens to be more fun than the others to remove> While there are likely excellent DIY's posted, that didn't deter me from charging ahead - besides, the RL search engine was out of focus for a few days.
Point of this post is to affirm some of the rumours about axle repairs ... and to emphasize the proficiency of air tools if you are a DIY type.
Firstly, the 32mm axle nut: in past years, I've broken numerous sockets & power bars getting that nut loose (339 ft-lbs), mostly on 928's .... no more! Hit it with an IR 1/2" Titanium air wrench, and it was off in seconds ..... same for the inner CV bolts. Simply use an extension to allow the air wrench to drop behind the rotor and line up with the axle to spin out the top bolt - rotate axle and repeat 6X ( the 3/8" will work here, but the 1/2" does fit too).
Next, the splined outer stub must be pushed inwards to release the axle: in some instances, mere thumb pressure will do this - not today! replaced the nut, covered it with a hardwood block, and caressed it mightly with a 2# ball pein ... nothing, so out came the MAC air hammer ..... ~20 seconds, and the stub was out.
The air tube (~3" diameter) must be removed, and the bracket securing the oil line to the engine case must be detached .... all this prepares you for the seemingly impossible gyrations to fish the loosened axle from the car.
It was relatively easy up to this point, as the car was on the lift: here's the deal .... the inner CV joint will only drop so far, and fetches up against the case. Actually, it is the subframe carrier that prevents it from dropping sufficiently. The way to get around this is to raise the wheel hub such that the inner CV end drops sufficiently to clear the case .... simple, with one exception - jacking the hub upwards elevates the car off the lift prior to the spring being adequately compressed!
The chassis must be lowered to have the three wheels touching the ground .... then jack the hub upwards until the whole car starts to lift: at this point, place a secure jack stand under the car, crawl under, pull down on the oil line ..... and drag the axle out. As you may guess, at this point there is precious little clearance under the engine, so your arm movements better be planned out before crawling underneath .... there is a lot of crawling involved!
Assembly, as the WSM always says, is exactly the reverse. I was fortunate to have a spare axle on hand, so from there it was a swap out - the removed axle will get fresh boots sometime later.
All this took ~3 sweaty, #@%&! hours to have the new axle in place .... and were it not for air tools, it would have been much longer> perhaps not at all, for the splines in this case did not want to release to a hammer.
Most things required on these cars is well within the sphere of DIY methods; however, some jobs quickly escalate into the heavy metal zone ..... and if you run short on the latter, remember how to get it back together for that humbling trip to the Indy ....
Closing the door on this deal after installing the second oil filter - and noticed an apparent 'line' on the outer right CV boot: rolled the axle, and voila ... a gaping split!
The right rear (RR) axle happens to be more fun than the others to remove> While there are likely excellent DIY's posted, that didn't deter me from charging ahead - besides, the RL search engine was out of focus for a few days.
Point of this post is to affirm some of the rumours about axle repairs ... and to emphasize the proficiency of air tools if you are a DIY type.
Firstly, the 32mm axle nut: in past years, I've broken numerous sockets & power bars getting that nut loose (339 ft-lbs), mostly on 928's .... no more! Hit it with an IR 1/2" Titanium air wrench, and it was off in seconds ..... same for the inner CV bolts. Simply use an extension to allow the air wrench to drop behind the rotor and line up with the axle to spin out the top bolt - rotate axle and repeat 6X ( the 3/8" will work here, but the 1/2" does fit too).
Next, the splined outer stub must be pushed inwards to release the axle: in some instances, mere thumb pressure will do this - not today! replaced the nut, covered it with a hardwood block, and caressed it mightly with a 2# ball pein ... nothing, so out came the MAC air hammer ..... ~20 seconds, and the stub was out.
The air tube (~3" diameter) must be removed, and the bracket securing the oil line to the engine case must be detached .... all this prepares you for the seemingly impossible gyrations to fish the loosened axle from the car.
It was relatively easy up to this point, as the car was on the lift: here's the deal .... the inner CV joint will only drop so far, and fetches up against the case. Actually, it is the subframe carrier that prevents it from dropping sufficiently. The way to get around this is to raise the wheel hub such that the inner CV end drops sufficiently to clear the case .... simple, with one exception - jacking the hub upwards elevates the car off the lift prior to the spring being adequately compressed!
The chassis must be lowered to have the three wheels touching the ground .... then jack the hub upwards until the whole car starts to lift: at this point, place a secure jack stand under the car, crawl under, pull down on the oil line ..... and drag the axle out. As you may guess, at this point there is precious little clearance under the engine, so your arm movements better be planned out before crawling underneath .... there is a lot of crawling involved!
Assembly, as the WSM always says, is exactly the reverse. I was fortunate to have a spare axle on hand, so from there it was a swap out - the removed axle will get fresh boots sometime later.
All this took ~3 sweaty, #@%&! hours to have the new axle in place .... and were it not for air tools, it would have been much longer> perhaps not at all, for the splines in this case did not want to release to a hammer.
Most things required on these cars is well within the sphere of DIY methods; however, some jobs quickly escalate into the heavy metal zone ..... and if you run short on the latter, remember how to get it back together for that humbling trip to the Indy ....
04-19-2013 | 10:35 PM
#3
Rennlist Member
Joined: Jul 2002
Posts: 16,523
Likes: 82
From: Bend, OR
You really gotta be careful using the impact on the CV bolts. I helped a friend drop the motor from his SC, and he tried that to expedite things. Not having the hex bit firmly planted resulted in two stripped bolts, which required Dremel work, that extened the time on the project by more that a few minutes.