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Discussion Starter · #1 · (Edited)
I'm not a mechanic I not do work for any company this is just what I've come up with

Seems a few are having airREX top mount and related issues because of this.

First of all I notice a couple of people are having problems with leaks but all their connectors are sealed. The problem is when the bus is dropped the lower ball joint is maxing out putting sideways pressure on the strut and if the top mount is loose it then allows it to move. When it's moved it puts extra pressure on edge of the top of the bag and damages the o ring seals in the top of the bag. I'd suggest replacing these 19x2mm o rings like I did which sorted this.

Top mounts

So I see some have had the new design of top mount through but are struggling to make these work. I think my bag is slightly smaller than others being from the very first design but it should help.

As you can see on the pics below my bag sits a little way down the stanction. If I was to run the supplied washer when the bus was jacked up with pressure in it I think it would over stretch the bag.



To stop this I made a sleeve




I then installed the smallest reducer for the spherical bearing. This still cleared my reducer when at its full angle



Now go ahead and fit the spherical bearing topmount and another small reducer. You want to use half nuts, I ordered these as they were a smaller profile than the supplied ones: Ebay half nut
Use an impact wrench to tighten down.
Ignore that theres 2 nuts on, I'll come to that. The top one there is actually what I deceded to run underneath



Now use another nut to lock the one off that you have just installed like the above pic.
I used a tiny drop of gearbox oil I had laying round to just lubricate the spherical bearing as its quite tight when new. You want to start working the bearing backwards and forwards to loosen it off, then use a spanner to hold the nuts and rotate to topmount. You want to ensure its turning on the bearing and not the reducers. Carry on doing this until the bearing has loosened completely off.
Remove the locking nut and once again ensure the topmount nut is tight.

This part of the strut should now be ready to install

Spring plate

For some reason air struts make the whole strut turn and from what I know this is what's causing all the headaches with T5 top mounts coming loose.
A MK4 Golf has a similar sort of design and they drill the turret top and install a different topmount but the T5 is double skinned there and creates problems

Now I'm guessing most of you have been running lock nuts tightened down to death that have been scoring the spring plate. I ordered these after market one just for testing and will be installing genuines. You will need these smooth and flat for later on.
Ebay spring plate

Where the rubber of the spring plate touched the top side of the turret I added grease. I did this because the design of the spherical bearing will now allow the strut to lean when dumped and it would help the spring plate move across slightly to help. I'm not 100% if it actually helps but it's worth a go.

You also want to order some 14.2mm needle thrust bearings, you local bearing supplier will sort this as the link for the place I used won't work.

Fitting

With the strut in place and pressure from underneath install the spring plate. Next install the needle thrust bearing with a light coat of grease and the standard 21mm flanged nut. This has to be the flanged nut to spread the load across the thrust bearing.

Nip up, do not ever tighten as you will crush the bearing!! You only need enough force to stop the topmount assembly moving in the turret!!



Have someone throw the bus lock-to-lock ensuring the topmount nut turns freely and isn't sticking or grabbing that would want it to come loose.

Do a road test minus the scuttle so you can tighten the topmount nut if needed to remove excess play.

I am also selling these on behalf of a friend over in Holland. He's water cut them from stainless steel,drop me a PM if interested



Once finished sit back and have a jagerbomb T:
 

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good write up dude and some clever thinking , will bear this in mind when i go for air
j
 

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Great help Shaun. I swear I'll get around to fixing mine at some point!
 

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Nice write up mate. Just a couple of things I'm a bit concerned about (not my product, so excuse me if I'm sticking my oar in where it's not wanted! And this isn't a poke at you at all Shaun)...

The rubberised top plate is no good with this design, the entire strut should rotate with the spherical bearing, so bag, body, piston rod. The rubberised top plate doesn't have a bearing it's self so the nut is likely to be coming loose and/or wearing down the top plate as the wheel turns. The spherical bearing it's self is OK but it should be secured to the body completely separate from the main assembly if that makes sense. It also doesn't give a huge amount of articulation. Spherical bearings in the traditional sense should be "free" to move in both rotation and articulation, otherwise it may as well be a standard bearing (which won't work on a T5).

Here's one I made a while ago, it's not for a T5 so the proportions are way out but same theory, as you can see it uses a completely separate mounting point to attach the strut to the body, in this case it's a massive lock nut (with a second one above it for belt and braces). The spherical bearing is therefore allowed to articulate freely. It's also supposed to be very tight in case you're wondering, I can see the need to loosen it up in the situation you have but a good quality bearing should be too tight to move by hand. It's kind of overkill using spherical bearings on a T5 and it's quite likely to transmit a lot of road noise up into the cabin but fair enough it's one solution.



Only other thing (again sorry not picking holes!), you shouldn't ever use an impact wrench on the top nut! But hey sometimes it's at your discretion, just don't let it rotate like mad.
 

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Discussion Starter · #5 ·
You are right Jonathan, I've been saying this to them for months!! I'm just trying to make work what is currently available and what people have.

With how I've done it here it allows the strut to turn on the spherical bearing and the thrust bearing on top of the rubber plate stopping the nut from coming undone. In effect its 'floating' there should you say.
Maybe the pic isn't clear as the needle bearing is so thin, here's a roller thrust bearing so it makes it a little more obvious to others what I've done




I also know what you're saying about the spherical bearing but with it being so tight it was turning on the reducers and undoing that half nut. I even tried wire locking one of them.

No No no don't use the impact on that top nut in the scuttle, just for the half nut on the spherical bearing but as pointed out though mate I'm not a mechanic.

I also looked into some top mounts like the ones you've posted and when I say Geoff you know which company I mean werent interested in sellinge any :*
 

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Thanks Shaun
can you confirm that this stops the knocking also not just fixes the air leaks
I guess by putting the spacer on the top of the bag this will keep the top of the bag in line with the strut and help stop the top of bag twisting over and knocking against the main shaft

Craig
 

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Discussion Starter · #7 ·
I've got no knocking but I only installed it like this.

No that spacer as discribed is to keep the bag from over extending. Air pressure will keep it straight as it was just the old top mount that had slipped that would have forced it over
 

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Discussion Starter · #9 ·
It's a shame the thread isn't longer on the top of the strut to run the roller bearing.

I may even try cutting a std flange but down and using it with the roller bearing
 

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I sort of don't understand the problems anyone is having with the Airrex T5 top mount, partly because I don't know the
difference between the early and later designs, If the later design is after Feb 2014, then that is what I have fitted, with no
knocking, squeaking, binding at all. The strut moves just as the original does, and I noticed with these pictures here, there is
not enough thread at the top to fit the damper adjustment, where I have fitted it with plenty of thread, perhaps someone
could post pics of the assembly order of all the parts to get a better understanding.
 

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Discussion Starter · #11 ·
I sort of don't understand the problems anyone is having with the Airrex T5 top mount, partly because I don't know the
difference between the early and later designs, If the later design is after Feb 2014, then that is what I have fitted, with no
knocking, squeaking, binding at all. The strut moves just as the original does, and I noticed with these pictures here, there is
not enough thread at the top to fit the damper adjustment, where I have fitted it with plenty of thread, perhaps someone
could post pics of the assembly order of all the parts to get a better understanding.
Your top mount the same as in the pic?
 

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No, the one shown in the pics appears different to what I have, what I have is like that shown in Airrex's advertisements,
with a cup on the top of the bellows to fit the VW top mount bearing in, the bearing is reversed - the metal side up -
the largish VW original metal plate under the top mount rubber is not fitted at all, leaving the bearing metal side contacting
the the rubber under-side, this means less contact on the rubber but mine has done 1000s of ks without problems, this
way of fitting will mean the air strut behaves just like the original and leaves plenty of thread at the top side to fit
the damper adjuster. The thread (damper rod) remains fixed, no turning.
BTW, I fitted new top mount bearings and rubbers, the old rubbers looked ok, but on close inspection cracks were found.
The top mount nuts were re-tightened once early after fitting, since then have been ok, I did use lock nuts for safety.

I hope this helps someone, I do have some pictures somewhere I could probably dig out.
 

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Discussion Starter · #13 ·
So I've done around 3000miles on this setup now, I had to swap out the needle bearings for the rollers as they didn't cope to well. I've used some loctite 243 just to help hold the 21mm flanged top nut and had no movement

The bearing I'm now using

 

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I've got some pictures here that might be of interest, or might help, I hope. They are fairly self explanatory, but please ask
if you have a question.





^ Shows the assembly order, the bearing upside down.







I'm still working out a way to machine the metal plate (in the first pic) to have it in the installation, but so far everything is
working ok, although i did have to tighten top nut after about 2k kms. that would be expected I think, with a new top mount
rubber.
.
 
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