Replacing Perentie steering shaft/uni-joint replacement

**cummo** · 5th July 2015, 01:42 PM

Am giving the Perentie a pre-rego going over - rego due in early August and for once I'm trying to be proactive and get in early rather than leaving it till the last minute - and have decided to try and reduce the steering play.

All the track-rod and drag link ball joints are recent replacements as is the drop-arm ball joint - no issues there. I then moved to the adjustment screw on the top of the manual steering box (nil P/S), and adjusted the pre-load a little via the Torx-head adjustment screw (front jacked up/wheels at full lock) - and it reduced it somewhat. A little tighter to turn through the range though, so I may revisit it to back it off a little.
I then checked the intermediate steering shaft uni-joints for play and I think this is where some of the residual play may be. There is very noticeable movement in the lower uni-joint, and barely, barely discernable play in the upper uni-joint below the steering column pillow block/bush.

I am planning to replace at least the lower uni-joint, however if the whole shaft comes out as part of the replacement procedure I'll replace both joints and/or the shaft if the uni-joints aren't an individual replacement part.
My question is is replacing the shaft/uni-joints a fairly straight-forward job or are there any tricks/tips it would help to know? I will mark everything pre-disassembly to be safe and will attempt to restrain the steering column in it's current position also. Any suggestions as to how to clamp/hold the steering column in it's rotational position would be appreciated too; not sure whether there is a clamping bolt/set screw to achieve this or whether it is a case of clamping/tying the steering wheel inside the cab. Post replacement of all bits I'll revist the steering box preload adjustment also.

Any advice appreciated.

Cheers, Dave

**JDNSW** · 5th July 2015, 02:37 PM

No clamp I know of for the steering wheel. The only catch I can think of is that the clamp bolts on the box and the upper shaft need to be completely removes to get the shaft out as they go in a groove in the splines.

John

**rar110** · 5th July 2015, 04:43 PM

Point both wheels straight ahead. Mark the shaft housing and upper shaft, and shaft against both unis, and bottom uni against box spline. Mark the new unis in the same place. You don't need to remove the upper shaft. Fit the new unis so marks all line up.

**cummo** · 5th July 2015, 07:00 PM

Thanks for the advice fellas.
I'm letting the joints soak in some penetrating oil for a while, and following cleaning up the splines as best as I can I'll mark at all joints - I'm a big believer in measure twice cut once - and fingers-crossed the joints will drift off the shaft ends OK and I'll be able to remove and replace both without too much bother.

Cheers, Dave

**rar110** · 6th July 2015, 07:27 AM

I use a white out or liquid paper pen to mark stuff like this.

**cummo** · 7th July 2015, 08:00 PM

Yep - bought some fresh White-Out yesterday. If in doubt, mark it anyway.

Cheers, Dave

**cummo** · 14th July 2015, 09:14 PM

Installed the new universal joints to the collapsible steering shaft OK, and nipped the M6 bolts up to 25Nm which is the figure I noted in a post on an AULRO forum (which was for a Discovery from memory). Just as a check I looked up the tightening torque figure for the steering shaft universal joint nuts in the manual for the Defender 90, - which I have a digital copy of - and the figure is noted as 45Nm. This seems way to high for an M6 bolt, albeit a Class 10.9 structural one. Just wondering if anyone has come across this issue before and whether the higher figure is erroneous.

Cheers, Dave

**JDNSW** · 15th July 2015, 05:28 AM

Originally Posted by cummo

Installed the new universal joints to the collapsible steering shaft OK, and nipped the M6 bolts up to 25Nm which is the figure I noted in a post on an AULRO forum (which was for a Discovery from memory). Just as a check I looked up the tightening torque figure for the steering shaft universal joint nuts in the manual for the Defender 90, - which I have a digital copy of - and the figure is noted as 45Nm. This seems way to high for an M6 bolt, albeit a Class 10.9 structural one. Just wondering if anyone has come across this issue before and whether the higher figure is erroneous.

Cheers, Dave

45Nm in my factory 90/110 manual - which would apply to the Perentie. It is possible the figure has been reduced on later vehicles, but it may reflect the the fact that the basic 90/110 (including Perentie) has manual steering as standard, so loads on this part are much higher. (I don't think Discoverys have ever been made with manual steering)

John

**cummo** · 15th July 2015, 06:20 AM

Just for the exercise I attempted to tighten one of the bolts to 45Nm, bringing it up slowly from 25Nm in increments of 10Nm which I thought would be reasonable given the bolt diameter. I felt the bolt yield - a bolt stamped Class 10.9 - at the first stage - 35Nm. A new full set of Class 10.9 bolts and matching nuts are on the shopping list this morning......
A quick Internet search gives a lubed assembly torque figure of 11 to 13Nm for an M6 Class 10.9 bolt and 8 to 9Nm for a Class 8.8 bolt - along way shy of 45Nm. Armed with a new set of bolts and nuts I think I'll install and tighten all of them to say 15Nm - 20Nm maximum.
Interestingly at least one of the existing bolts is stamped Class 8.8, so either the steering universals or at least a bolt or two have been replaced in the past.

Cheers, Dave

**cummo** · 15th July 2015, 07:16 PM

My apologies John ? for some reason I had M6 in my head as the diameter for the steering shaft universal clamp bolts; they are actually M8x1.25 pitch.
Notwithstanding this, the recommended lubed assembly torque for M8 x1.25 pitch Class 10.9 nut and bolt assembly is approx. 37.5 Nm to give a clamp load of 75% of fastener proof load. Based on this criteria 45Nm for the uni joints still seems high. The bolt which yielded on me could have been fatigued, and perhaps brand new bolt sets would tolerate the higher torque, but an additional 10Nm on a relatively small diameter bolt is still significant.
In the absence of anything that suggests 45Nm is wrong I think when I install the new M8 x1.25 pitch Class 10.9 bolt sets tonight I'll aim for 25Nm in incremental steps, and if all goes well I may bump it to 30Nm.
Thanks for your interest.
Cheers, Dave

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