LS400 steering wheel telescopic-tilting mechanism

[Razor61]

The telescopic and tilt mechanism on my 98 LS400 has been bugging me cos it’s noisier than I think it should be. Some cars I looked at had a quiet mechanism. Sounds like the telescopic motor is struggling for some reason but it all works ok.
So last week I decided to have a good look at how it all works, my car has a different mechanism to the 99/2000 LS400. The 99/2000 is very similar to the LS430. If you look on the EPC website you can see the difference.
So last Wednesday evening I removed the covers around the steering wheel to see if I could see and then get to the sliding tube for the telescopic bit and the gear assy for the tilt bit (which is a proper piece of kit and engineering, it’s impressive)
I could get to both of them and applied some grease using a syringe, worked the mechanism’s up and down to get the grease moving around. It made a bit of a difference but nothing drastic. I suspect the guides mentioned below need some attention.
The telescopic bit has 2 spring loaded guides underneath to keep the tension and stop it moving around but has to be torqued to 8nm iirc so it’s not too tight. I have the workshop manual to adjust it all etc but didn’t fancy doing it at the time and it’s a journey into the unknown plus I was going on holiday Thurs until Monday in the wife’s IS250. I thought I’d set the interior light to ‘door’ on the car but turns out it was ‘on’ so came back to a totally flat Battery when I went to the car Tuesday morning, rookie mistake but a good charge all day Tuesday and overnight fixed it.
Over the weekend the thought crossed my mind to buy a second hand assy, have a good look and work out what I need to do to make it quieter without experimenting on the car. Of course if the price is low enough.
This morning I found the correct assy complete with all the motors on eBay and promptly bought it for £45 delivered, result. When it arrives I’ll have a good look and work out what I need to remove, clean and grease to hopefully make the assy on my car quieter and smoother.
I’ll take pictures and document anything I figure out and post it here which may be helpful to someone.
 

[Malc1]

the clear advantage of the older Mk3 is that the fix for this, well, the up and down part of it, is a twopenny steel washer ......  thankfully  ✌️

Malc

[Razor61]

2 hours ago, Malc1 said:

the clear advantage of the older Mk3 is that the fix for this, well, the up and down part of it, is a twopenny steel washer ......  thankfully  ✌️

Malc

Ah yes, the steel washer fix for the tilt mech plastic gear..........same setup for the mk4 or series 2a as well up to 08.1998. The same main assy was used on the LS400 for production dates 10.1994 - 08.1998 - the tilt motor part number changed but looks the same. 08.1998 on uses a different type of mechanism.
My 1998 mk4 or series 2a with production date of 01.10.1997 has the same tilt motor mechanism as the mk3 or series 2 using a worm drive with the plastic gear.
I'll look into the plastic gear thing when I get the used assy. I'll maybe investigate making a new plastic gear, just out of interest.

[Malc1]

20p must be the cheapest and simplest fix ever on a car for this issue ....  bet a Bentley or a Mokka costs shed loads more eh !

Malc

[Supafly]

I hadn't realised that this was an issue until I sat in my 'new' to me LS400.  My first blue 98 LS400 whirred away when you put the key in the ignition and I just assumed that's how they are....

When I put the key in the newer to me 2000 LS400 that only had 60k miles it was silent, so much so that I had to look to see if the wheel was moving!

Watching this with interest, as now I've heard the silence, I cannot un-hear it and want my older car to be just as quiet.

[Cotswold Pete]

My Mk4 was always noisier than my Mk3. 

I would add my Merc 350 has manual adjust, so reallty appreciate what I had when I owned LS

[Razor61]

Ok, received the steering mechanism today and had a good look at how it all works. First thing the tilt plastic gear is in perfect condition, I think the worn plastic gear is caused by owners using the steering wheel to lever themselves out the car while the steering mechanism is returning to its default position. This puts a lot of pressure/strain on the tilt plastic gear and therefore wears the plastic teeth. Better to wait until the steering mechanism has stopped before getting out of the car, which is what I do.

The telescopic part is held in place by 3 rollers, 2 flat rollers on the bottom and 1 ‘bobbin’ type roller on the top.

Top roller:

This roller is held in place by a roller ‘carrier’ with a pin through the carrier and roller. I knocked out the pin and removed the roller carrier and bobbin style roller. Cleaned the roller , used some scotch bright pad to remove slight corrosion on the roller, applied some moly grease to the steering shaft through the vacant hole, applied the same grease to the roller etc.

 

 

 

[Razor61]

The bottom 2 rollers are held in place with a very large grub screw and is locked in place with a large locking nut/ring.
Flat roller contacts the steering shaft, 3 concave washers ( concave side up towards the steering shaft and roller assy) then the large grub screw and locking nut. I used a paint pen to mark where the grub screw is, removed everything, cleaned with brake cleaner, greased the roller assy, applied grease to the steering shaft through the vacant hole then reassembled both rollers.
Of course it’s easy out of the car but I’m pretty sure I can do the same thing on the car no problem, I know now how it all works and what bits to remove and reassemble.
spanner used was a 32mm, I think it’s a 31mm nut but 32mm did the job.