Tub Fitting Conundrum

[meesonia]

Hello

Started to fit the painted tub back on the chassis. After a few attempts it won't quite sit down on the forward 4 bolt fixing pads. Checking underneath there is approx 4 or 5mm gap, roughly equal side to side. The rear part of the tub just forward of the diff bridge I can clearly see the tub is sat on the rubber strips.

If I get number 2 son to carefully stand on the forward part of the sill, the bit that is hidden behind the front wing, then the gap closes up. He gets off, it opens up again. We didn't spot this at the pre paint build up, so maybe something had got slightly sprained. Am I worrying needlessly and should I get No2 to stand on the sill whilst I tighten the bolts? Or just tighten them without him. Don't want to store up alignment problems for later by doing this.

Thanks in advance for your advice.

Cheers

 

Ian

[TR 2100]

I think you are assuming the chassis is rigid and doesn't bend.

What do you think will happen to the chassis when the tub is
fully trimmed, engine and gearbox in place etc.?

I would say your clearance is just about spot on, certainly
nothing to worry about (although you don't say what chassis
mounting pads you have fitted.

AlanR

Edited May 18, 2019 by TR 2100
Addition

[Peter V W]

Ian,

As a starting point:-

I would maintain the correct dimensions from the "A" to "B" posts and pack to suit.

It will take some trial fitting of the outsider panels.

Take your time, you can adjust a lot with the packs and bolts.

Peter V W

 

[meesonia]

Thanks for the replies guys, just to clarify the chassis is laden, ie engine & gearbox in place. under both the tub 4 bolt A post fixing point & the 3 bolt B post fixing point I have fitted the standard 3mm thick metal plates sandwiched between the 2 rubber pads.

Cheers

 

Ian

[Waldi]

Ian,

did you stiffen the tub with bracings before lifting off and are they still attached (fixed). If so, the tub is the basis and I would add 2x3 mm additional shims to compensate for the 5 mm. Make sure the body tub is not restrained anywhere and free to move vertically.

My chassis was close to the WSM dimensions (within just a few mm here and there) and once I fit the panels I had to move and add  shims anyway to get the correct gaps.

I achieved good door gaps on my 6 (all within 4.5-5.5 mm) with just altering shims. This took several days of making a change, think about the effects, make the next change etc. I was not in a hurry:)

Example: removing 3 mm rubber shim at the B post resulted in a 2 mm narrower gap at this side but also changed the bottom of the door shut line. Get the idea?

Good luck, think twice, act once (or twice) Waldi

 

[meesonia]

Hi Waldi

Thanks for your comments, I'm ok with understanding of fitting the shims, both adding and removing to achieve the gaps. I have improved the situation by lifting the tub off the chassis 50mm or so then lowering back down, it does seem to sit better now. Just a bit puzzled by your last paragraph that you took 3mm rubber shim from the B post, I thought the idea was the tub generally sat on the rubber strips on the chassis? That means your tub generally must have been sitting high off the Chassis, as you can't physically sit the tub any lower than the chassis. Unless I've mis understood, which is quite likely.

Ian

[Waldi]

Hi Ian, 

Good you sorted it.

On the B-post shims:

Removing the shims at the B-post helped me to correct the shut-line at the bottom side of the door as well, it was narrow at the rear end of the door. 

Lifting the rear end would only have reduced the upper B-post gap, but not improved the door bottom gap.

But I guess several roads lead to Rome.

Regards,

Waldi