MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG TD TF 1500 - Floorboards for TD

A few years ago, one of the first projects I undertook was replacing the rotten floorboard on the driver's side. Unfortunately, I didn't have a layout for the floorboard, so I made it by measuring the broken and rotten one and guessing whenever I had to. Worked OK, but now I'm working on the transmission tunnel and have realized that it doesn't have the bolt holes in the right places. (The transmission tunnel was missing quite a few bolts holding it in place).
Now I have redone the transmission tunnel and can see how it all fits together, I'm thinking of redoing the driver side floorboard and making a new one for the passenger side. I've found the excellent diagrams provided by Roy Challberg.
But before undertaking the project, I started looking for available materials, and can't find the right thickness marine grade plywood in town. I can probably order it, or I can make do with high quality birch ply in the correct thickness, but while researching, it occurs to me that other materials might be better. There is a marine grade plastic now used instead of ply in many places (called Star Board) and there are other choices as well, phenolic plastics (the kind used for table saw inserts etc) and of course, aluminum plate and diamond plate might make good replacements.
As these would be rotproof, waterproof, and probably stronger than plywood, I'm just wondering if anybody has gone ahead and done this, and if so, what materials they chose?
Thanks!
Geoffrey M Baker

The exhaust runs very close to the floor Geoff, the muffler especially, so you might find some pretty noxious fumes emanating from your plastic floor once things start to heat up. I used marine ply with a waterproof membrane then painted it matt black. Cheers
Peter TD 5801
P Hehir

Geoffrey -

Google "Plywood" in you local area. You will probably find 3/8" marine plywood at most of the plywood suppliers. Home Depot and Lowes won't have it.

I paid about $65 for a 4' X 8' sheet here in Orlando.

This document on my Google Drive may help you with the fasteners. (Left Hand Drive) A couple of locations near the pedal box need updating, but it is pretty near right.

Click on the link. Then click on the "Download" icon near the top center of the screen to download. A downward pointing arrow with a bar across the tip.

http://drive.google.com/file/d/0BxisXBEpc-IWa25XaHc4akNPd28/view?usp=sharing

Lonnie
TF7211
LM Cook

Thanks Lonnie, another great resource!
Geoffrey M Baker

I went to the local lumber yard and it was there the next day.

Jim B
JA Benjamin

Geoffrey,
I have installed 9mm phenolic plywood floorboards on my TD. No problem whatsoever, tough as nails and hard to beat. It will certainly outlast me and no need for painting. Seems to be the done thing over here. Just make sure you seal the edges.

Regards
Declan
D Burns

I picked up a sheet of 60x60 inch 3/8 high grade birch plywood from a local woodworkers store. It should do perfectly.
I'm printing up Roy Chalberg's floorboard diagrams v6. Anybody has any updates to his information or suggestions or alterations?

Thanks!
Geoffrey M Baker

Geoff -

Buy a sheet of Masonite or cheap panneling, too. Cut the cheap stuff first to match the pattern. When it finally fits perfectly, then you can use it to pattern-route the floorboards. Even though my floorboards are OK, I wish that I had done so.

Also, don't drill the holes for the driveshaft tunnel, gearbox cover, etc. Bolt the driveshaft tunnel in place. Then set the floorboards in place. Mark and drill the holes for the tunnel and toe board and bolt into place. Set the gearbox cover in place and mark, drill, and bolt into place. Finally screw to the wooden outer rails.

You may need to shim between the floorboards and rails. Seems like the jury is out on the subject.

Lonnie
TF7211
LM Cook

I think that's great advice, Lonnie. After marking out the driver's side very carefully, I've realized that the compound curve is simply too inaccurate for really precise fit. So I'm thinking what I will do is take a cardboard sheet (I can get ones big enough no problem) and mark that out as well, and then trim and fit it very carefully along the curve till I have a fit that actually fits my car. Then I'll transfer that to the ply. I'm also thinking... there are no screw holes along the whole left side of the sheet, for 40+ inches, and I could easily add three so that the entire sheet can bolt down snugly along both sides.
Geoffrey M Baker

I used the V6 drawing for my Td, and had to make a few adjustments to the hole positions and the back part behind the seat. Over all, very close though. I was able to take his drawing and make a 1-1 dxf which I just ran on the mill.
Dan Gill

The biggest mistake people make Geoff when making & fitting a replacement floor is not checking that the floor can be subsequently removed without having to take out the trim. This is only a problem if the trim is yet to be installed. If your car has its interior trim fitted then you should be fine but do pay close attention to the fit at the front quarter panel. Cheers
Peter TD 5801
P Hehir

Peter, my car has the underdash and front side trim removed. You are saying I should install the trim first and then cut the floorboards?
Geoffrey M Baker

Geoff, you need to be sure you can subsequently remove the floor without having to remove the trim. Originally the trim finished below the level of the floor. However you do it, just ensure the floor ends up clear of the trim. You should be able to remove either the floor or the trim without having to remove both. Cheers
Peter TD 5801
P Hehir

Well, I removed the floorboards. Easy on the driver's side - I put that one in new 5 years ago - but the left was in bad shape and I tore one captured nut box and had to destroy a couple of other screws to get it out. Interestingly, the compound curve is quite different on the passenger side, it follows quite a different curve. I'm glad I didn't just go ahead and cut following the pattern - I'm going to use cardboard as an outline to make sure the template is right before I cut either side.
Geoffrey M Baker

Found some interesting stuff of course while taking things apart.
1) I found two wrenches (including a nice Whitworth one) that had fallen along the side of the floorboard. Nice!
2) Discovered I was missing two essential bolts that hold the tranny tunnel in place plus a few cheesehead screws on the passenger side. I imagine this made the ride a bit more rattly...
3) Found both floorboards diverge from the published patterns, by quite a bit. On the driver's side, the bottom rounded corner is far more curved than my pattern suggests, and the passenger side has a wider and quite different arc to the curve.
4) There was felt stripping under the floorboards. Some threads indicate this shouldn't be there - I'm going to put some kind of rubber strip down.
5) Had to cut off one cheesehead screw and destroyed a couple of others - always the case when working on something 70 years old..
I've cut the drivers side floorboard and will cut the passenger side tomorrow. I've got the driver's side cut out completely and routed out on the underside where needed.
I intend to add extra cheesehead screws along the outer sides, as the original design really have none except at the top and bottom. This will make it all tighter.
I'm pleased that when reassembled, I think I will have all screws and bolts in place, when quite a few were missing originally, and good insulation through weatherstripping using rubber strips under the floorboards.
The new floorboards will have enough space to remove with the trim in place, I am making sure of that - thanks Peter.
Lastly, I just want to thank everybody for their helpful input, especially Lonnie Cook who emailed me with pictures and helpful advice, all far behind the call of duty... this forum is such a great resource!
Thanks all!!!!
Geoffrey M Baker

Very successful! Using cardboard templates, I was able to use Challberg's diagrams and cut floorboards for both sides that are a good fit. I strongly advise this because the compound curve on the diagrams is only approximate, and good probably only on Mr. Challberg's car... every one is different!
Once I had the plywood cut and routed, I fitted it in and spent a painful hour sliding around under the car (no, I don't have a nice floor lift) using a tiny brush and blue paint to mark the holes. Then I drilled them out and put the boards back in for a final fit. All but two of the screws fit nicely in. The top right screw on the driver's side was blind (I couldn't find it underneath, I think it's above one of the main members) so I used the diagram for the placement of that hole.
Both boards fit perfectly with all screws fitting in.
I then added a little routed strip under the V cut on the passenger side, as recommended by Lonnie Cook, and they are now getting their first coat of varnish to seal the edges and faces.
Looking back on it, I think I would have made my first cardboard test templates a bit bigger all round and then hand cut to fit; there are a couple of areas that could have had more wood. I also highly recommend doing all screw placements with the boards in the car, as my car certainly wasn't an exact match to Challberg's diagram.
When fully painted, I'm going to put some sort of a weather seal all around on the bottom (perhaps just some adhesive foam strips); this will keep water out and vibration down.
Once all back in place, I can return to the original job... getting the bellhousing shroud to fit correctly.
Geoffrey M Baker

Ridiculous discovery today. When disassembling the bellhousing shroud, I carefully put the screws in a bag so I'd know which were correct when replacing, right?
Today I discovered that some moron PO had substituted the correct BSF 1/4 thread screw (which screw into four captive nut housings on the floor/kick panel or whatever that piece is) with four big selftapping screws. They probably destroyed the captive nut threads when they forced them in, I'll find out tomorrow.
Just one of those annoyances that makes you throw down your tool and go get a beer. Enough work today.
Geoffrey M Baker

They don't really get torqued down very much so I suspect that you could probably run a tap back through those captive nuts and re-align most of the original threads... at least enough to hold the bolts securely.
Kevin McLemore

Today I didn't get around to the problem with the bellhousing screws. Instead I finished varnishing and painting the floorboards and installed the 4 T nuts for the bellhousing shroud.
I didn't install T nuts for the seats because I think they are a bad solution. Instead I'll do what I did with the old driver's side floorboard - I'll install straight bolts with large, thick washers (2 inch diameter). I think these would hold much better in case of an accident; small T nuts might just tear through the wood. I might even take a straight piece of metal and drill two holes, to increase the area of support beneath the plywood.
Tomorrow I'll work on cleaning/scraping/painting the support frame, getting rid of the rust and getting to bare metal and painting it. Then I'll install the underlayment. Soon I'll be back to where I was two weeks ago, and be ready to reinstall the bellhousing. Amazing how easy it is to get sidetracked.
Geoffrey M Baker

This thread was discussed between 28/10/2015 and 03/11/2015

MG TD TF 1500 index

This thread is from the archives. Join the live MG TD TF 1500 BBS now