MG MGB and MGB GT Tech Talk
What size bolts hold the rails to the floor pan? The nuts in my floor pan have been painted over so I will also need to tap them out. I know the car orginally had spacers between the rails and floor, I thought about using seveal washers, do you think that would work?
Don't know the size...but cannot you just clean out the paint instead of replacing them? That could be a bear! Also, Gerry makes spacers I believe...he's got a page on www.shadetreemg.com with all he does.
They are a 7/16 as I recall in fine thread. I do not know if that is enough info for you. I believe a stack of washers would ok.
The original bolts had a taper at the end that works wonders on getting them into the captive nut in the floor. Be careful tapping the old nuts. The welds or the metal around them are often one of the first things to rust out in the floor.
!/4 x28 or 1/4 SAE. The original bolts were pointed to allow easier alignment at assembly. If you use washers, superglue them together so that they act as a single spacer while assembling. A bolt screwed up through the rear weldnuts aid in getting everything lined up. Drop your spacers on this bolt then back it out as you screw one in from the top. Leave the back bolts loose so the rails will be able to lift to allow you to insert the spacer in the front. Removel of the seat slide stop block on the rear of the outside rail will allow you to move the seat back further and give you better access to the front bolts. If your carpets have holes cut in them to allow the spacers to rest on the metal floorpan, use 1/2 thick stack of washers, if the spacers will be on carpet, ues only 3/8" thickness. While your seat is out, lay a straightedge on the seatrail that bolts to the seat bottom and check for straightness. Every seat I have seen has the rail bolts too tight so that the rail is not straight, this makes for a hard sliding seat. I supply new stainless bolts pointed as originals were and new spacers with my seat packing kits. I recomend that you replace the old bolts with stainless, or at least antisieze the old one when you replace everything. Maybe the next time they come out they will do so without ripping the weldnuts out. Hope this helps
Thanks Gerry! Even Lindsay Porter does not give that much detail!
My pans are in OK to bad shape, a few patches and small holes here and there. I will want to replace them sometime in the future. But for now, I want to make it a driver. The PO, painted them with some type of thick black paint as a sealant. That goop is in the captive nuts. I'll let you know how it works out.
I used that aerosol "orange" paint remover to remove all the goop from my floorboards. Worked like a charm. Picked it up at Home Depot along with a TON of rags.
Originals were about 1" and pointed. I use 1.25" and pointed because it makes for an easier installation
I believe the ones I use were about 1 1/4" as well. I had to use ones longer than the original because I put some 1/2" padding under the carpet to help quiet down the interior.
Trent
The originals are semi self tapping; they have swirls in them to rid grit and such.
Never seen anything self-tapping on a MG except a wood or sheetmetal screw. Seat bolts were plain old bolts with pointed tips, just like you will find around the radiator and any other place that has an alignment problem
Actually, Gerry, my 79 has the semi-selftapping bolts Chris describes. I thought they were rather odd, and have since replaced them with UNF 1/4-28. I did have to run the tap through the captured nut to get the UNF installed. Maybe the later years used the self-tapping type.
Ed
