Sprint sub-frame torque and steering column bush washers

[olr159w]

Hi.

I'm hoping someone can provide some help with a couple of issues. Thanks in advance.

I have a 1980 Sprint that got exported to it's current home in Perth Western Australia. It doesn't get driven a lot truth be told and for the last "a long time" it has been pending getting a few things fixed. Firstly it was the rear axle seals but that has then turned into a realisation that a few suspension bushes need replacing.

I have two current issues.

Firstly regarding the rear sub-frame bushes. It had poly ones during a rebuild but one had split so they are being replaced. It's the NS one that split and I started on that side. The bolt came undone OK revealing everything is basically sound - a bit of surface rust on the chassis leg under the washer bush and the conical washer is a bit tired. At this point I've zinc galv painted it and re-used it but might replace it. It's just tedious ordering stuff from the UK in the middle of the job.

Here's the thing though. The WM states a torque of 48lbft. I started tightening and got to maybe 30 when the washer bush was looking very compressed and splayed. I figured it would split and backed off. The sub frame is on axle stands so its all sitting there mid-job. Also I'm using superflex ploy bushes for the new parts.

I realise the front sub-frame bushes have a spacer tube but there is no such part on the rear ones so I can't see how the suspension bush would ever withstand 48lbft. As far as my car is concerned the connection part sequence starting in the engine bay is : bolt, large steel washer .... bolt through chassis leg (in tube as I understand it)... flat washer bush, sub frame, shaped lower suspension bush, conical washer, nut.

I've asked superflex for an opinion about this. Also the person who rebuilt the car 12 or so years ago. There are two different opinions.

One is the chassis leg has a protruding tube (extension of the tube within the chassis leg?) that passes through the washer bush and abuts the top of the conical washer, thereby you'd assume, enabling the whole thing to be tightened up to 48lbft in just the right way that its all tight and the suspension bushes are acting as a clamp but not compressed to destruction. The other opinion is that there is no protruding tube at all and the washer bush simply sits between the chassis leg and sub-frame with the whole thing appropriately tightened - 48lbft being too much.

So which is correct? There is no protruding tube on my car nor any sign there ever was. When I finally get to the OS one - totally inaccessible due to steering linkage - I will compare of course. I can't help thinking that if there was a protruding tube it would have to be exactly the right length otherwise it would either do nothing (merely acting as a locating spigot for the washer bush if it were too short) or would cause insufficient clamping of the arrangement if too long ie causing a bolted join between the metal parts and rendering the bushes useless). It just seems a stretch to imagine the mechanism would depend on this and that it would be reliable.

If it turns out a protruding tube is supposed to be there I have some awkward issues. I'm not sure how that would be accurately fixed and not in a rush to visit a welding shop anyway. Could washers be used ? But then of course there's the issue of what depth of washers would be required. If there is a protruding tube can anyone advise how much it protrudes?

Second question is much shorter. I'm also replacing the bush where the steering column goes through the bulkhead. Probably impossible to remove the column due to wiring bulk and so the parcel shelf will have to come out too. But the column is clear of the hole so I think I can work this without full column removal. The WM talks about two washers around the bulkhead bush - a steel one on the engine side and a plastic one on the inside. I assume to limit wear on the bush? I have the steel one but the plastic one is not there. Does anybody know where I could get the plastic one or, if I made something myself, how thick it needs to be and what material could be used to make it? (and what is the original made of? )

Thank you

Mark

[xvivalve]

There most definitely should be a protruding tube coming out of the bottom of the chassis leg, by about 22 mm if memory serves me correctly.

The tube is not part of the OE chassis leg, they come with just the hole, so a replacement chassis leg whilst OE were readily available might be the cause of this if the original tube had disappeared at that time?

Aftermarket chassis legs generally come with the tube welded in place with the correct protrusion beneath.

[James467]

The WM talks about two washers around the bulkhead bush - a steel one on the engine side and a plastic one on the inside. I assume to limit wear on the bush? I have the steel one but the plastic one is not there. Does anybody know where I could get the plastic one or, if I made something myself, how thick it needs to be and what material could be used to make it? (and what is the original made of? )

I found this as well, have a look here, near the bottom of the page and possiblt the next one. The general concensus is that there may have been an intention to fit it but it was then deleted.

As for the subframe bushes, from what you described it sounds correct, only the fronts have the seperate subframe spacer or tube that you describe. I have the standard rubber bushes on mine and they torqued up to 65nm with no problem. The tube going through the chassis leg kind of sticks out of the bottom thus forming a bit of a tube that the bush goes around, has this corroded away allowing you to crush the bush down too much? Also, is it the torque wrench? Don't take this the wrong way, I've tightened things down before only to see that when I double checked I'd set the wrong torque!

This is the club chassis leg (thanks Alun) hopefully demonstrating what I mean!

chassis_zpsctbxcmnc.jpg (69.65 KiB) Viewed 2043 times

If you think of the weight of the body on them plus the engine in the subframe bouncing around and pulling on them then I would imagine theres more force than that on them!

Edited slightly because Alun got there before me!!

[olr159w]

Thanks for the replies.

Once again the car looks to be fighting getting back on the road, tooth and nail. It kinda ticks me off to be honest. Could it be any more bloody difficult? It must have been on axle stands for about a year.............

Taking each of the topics in turn :

Sub-Frame Bushes
NS has chassis legs in good condition but no protruding tube and I strongly suspect there never was from when it was rebuilt. Car is in home garage on stands and prospect of adding a protruding tube is nil. I'm not even sure whether it's practical to add a protruding tube by now welding one anyway - it'st way too inaccessible. Plus I can imagine sourcing said tube would not be easy either. So really the situation looks pretty disastrous.
OS I am yet to examine but the old washer bush is still in one piece. I can imagine that without this clamp arrangement properly in place a lot of the load would be taken by the washer bush rather than the cone shaped bush also but I just feel that's the case, not sure I could explain why.... ! The OS may perhaps be OK but it's more logical to believe it has no protruding tube either and it's just that the bush hasn't let go yet. Chassis legs on OS otherwise OK I'm 99.9% certain

The idea that the conical washers locate on this protruding tube and that this union is supposed to be accurate and durable (esp re risk of ongoing rust) I find almost totally unbelievable.

I'd welcome some suggestions for a way forward bearing in mind the car is sound and access to welding is going to be a pain (even if welding a tiny tube on it is possible)

I'm thinking I would get new conical washers since their utterly perfect condition must be critical. As to the tube I'm wondering if I can fake them with washers?

Can anyone confirm for certain the extent to which the tube must protrude?

Steering Column Washers
I'm confused on this. I have a steel washer seemingly permanently fitted inside the bulkhead and no plastic washer. So first of all are we saying that the general consensus is that the plastic washer was never used and to not worry about this? I'd assumed the two washers were there to avoid wear on the bulkhead bush.
Secondly I had perceived the steel washer goes inside the bulkhead plate (ie where it is fixed) so that the column pass through the bush, then the steel washer, then the bulkhead plate and then locates into the splines. Meaning in other words the bush pushes into the washer and bulkhead plate from the inside? I'd then assumed the phantom plastic washer sits the driver side of the bush protecting its "back" from the flanged end of the steering column assy.

But looking at that other thread there seems to be the idea that the steel washer is inside the engine compartment? Is that right? How does that work - flat against the bulkhead plate so the bush pushes through it as well or on the outside face of the bush? One of the photos seems to show the latter in which case what is the purpose and what stops it rattling about?

Thanks

m

[xvivalve]

The club chassis legs use electrical conduit tube for the tube element and it is only fixed to the underside of the leg via a square reinforcing collar welded flat to the underside of the leg. Just run a drill down the tube when cut to size to remove any welding burr from when it was fabricated.

22 mm down projection confirmed, overall length of tube 91 mm

[olr159w]

Thanks for that info.

I have to admit I don't get how this all works. I just measured the thickness of the washer bush and it's 11mm. So if this tube projects 22mm that obviously means 11mm beyond the washer bush.

Beneath the washer bush we have the steel of the sub frame of course but this isn't a box section so lets say 2mm. That leaves us with 9mm of tube beneath the sub frame.

The thickness of the upper part of the cone bush is 5.5-6mm so we're looking at 2 or 3mm of tube sitting proud of the lower side of the cone shaped bush.

If I tightened the conical washer against that surely it would clamp anything? Everything would have 2-3mm of play? Particularly bearing in mind these measurement relate to a perfect non compressed fit.

I would have though the tube should protrude, say, 11+2+5 so that when the bolt is tightened against the conical washer it is possible for it to actually compress the two sub-frame bushes a little bit.

rgds

[olr159w]

One other thought for your opinion while I'm off away sleeping (7hrs ahead of the UK)

I'm wondering about the top hat style tube spacers on the front sub frame mounts #159211.

I'm thinking a solution might be to slide one of these over the mounting bolt such that its base abuts the chassis leg. It relies on the spacer being at least 22mm long (although the doubts about tube length still stand for comment please) so that it can be cut to size if required. It's not critical that the tube be welded to the chassis rail and this would provide a solution to the protruding tube problem.

?

m

[DOLOMITE 135]

The tube is not part of the OE chassis leg, they come with just the hole

Slight correction, the OE chassis legs (part numbers 715865 & 715866) incorporate the tube.
The tube protrudes 20mm from the reinforcing disc around the mounting.

[olr159w]

Thanks.

So if it's 20mm from the reinforcing disc around the mounting how far is it from the actual chassis leg would you say?

Is the reinforcing disc 20mm bringing us back to 22mm or something else?

Also can anyone help with :
1. view on using no welded tube (pref front subframe spacer if long enough) to act as the protruding tube

2. with a perfect set-up correctly torqued how much compression is there on the washer bush and the cone shaped lower bush? It still seems to me that the protruding tube length must be critical if the conical washer tightens down on the end of it otherwise the bushes could be either loose or over crushed. I can see that if I use spacer tubes there may be some experimentation hence this Q

thanks

mark

[xvivalve]

The tube is not part of the OE chassis leg, they come with just the hole

Slight correction, the OE chassis legs (part numbers 715865 & 715866) incorporate the tube.
The tube protrudes 20mm from the reinforcing disc around the mounting.

Well it doesn't on the ones I have!



Using the front 'top hat' tubes on the rear would mean having to also change to the flat bottomed bush and large washer; I don't think it would be satisfactoty...

[olr159w]

I don't see a need to swap the bushes if using the top hat spacers on the rear.

All I am thinking is using them to mimic the welded tubes that I don't have. So the flange of the spacer would sit against the chassis leg aligned with the hole. The bolt would run all the way through of course. The spacer would be cut down to ensure 22mm protrusion - if that really is what it is which I still find odd in terms of all the relative sizes - and the flange would also act to spread the load on the chassis leg. The conical washer could be tightened against the spacer/tube and all should be good.

I might need to reduce the flange dia to ensure it sits inside the washer bush internal dia.

And again the extent of the protrusion is critical or either the bushes wont be clamped or they will be over crushed.

?

m

[DOLOMITE 135]

Well it doesn't on the ones I have!

These all include the tube and reinforcing disc, so maybe yours is incomplete?

[xvivalve]

Curious, I have three without acquired at different times from different sources; checking the book though and there's no separate part number for either the tube or reinforcing plate; I sit corrected!

The top hat tube is only 38 mm long.

[DOLOMITE 135]

The spacer would be cut down to ensure 22mm protrusion - if that really is what it is which I still find odd in terms of all the relative sizes

The perspective is slightly off in my photo below but the tube protrudes 20mm from the reinforcing disc, and a total of 22mm from the chassis rail.

Hope this helps.

[olr159w]

A massive help everybody, thank you.

I intend to use the top hat spacers as fake protruding tubes. Suitably cut down to the right length they should be almost perfect. Their only issue is that the flange OD is 1 inch whereas the washer is 3/4 meaning it wont sit flat . Choices are reducing the flange OD, getting some large 1 inch ID washers or not using the flange end at all.

Regards

Mark