More fastener questions

[Keith L.]

Early 70 LT-1
1. Shifter bracket to frame. I don't know about the heads on two of these???

2. Rear pinion cushion. The bolt and large washer appear to be silver cad. What about the smaller washers and nut?

[Keith L.]

Re: More fastener questions

3. The fasteners for the lower control arms. AIM shows lock washers only. My 70 had lock and flat washers. A 75 I parted had only lock. Any others have flat and what finish for lock and/or flat washers? I feel sure the arms had never been off the car.

[Edward J.]

Re: More fastener questions

Kieth, the pinion snubber nut and washer I believe were black phos. the other two bolts I have never seen I think just a hardware store or sometime like that.

I looked in my 72 AIM it shows only lock washers, but who knows, Someone had flat washers in front of him that day. If the control arm appears to have never been off ,go with what you have documented there, I am sure there are others out there set up like your car.

[Keith L.]

Re: More fastener questions

I know the tranny had been out before. So Those two with the unfamiliar headmark are wrong?

[Chuck S.]

Re: More fastener questions

PAI headstamp is not one I recognize, either from my own 70 or judging other 68-72, but my experience may be limited.

The front support bolt headstamps on my car are RBW, but there are likely other headstamps. This fastener is shown on AIM 7B2, Item 4, is 3/8 NC X 7/8" Lg...check the dimensions for consistency. My notes show the lock washer as black, but the plain washer I show as cad...interesting. The rear support screws are also black phosphate.

Pinion bumper lock washer, washer, and nut (4A4, Items 3, 11, 7) I show as black phosphate. I don't have anything on the bolt or the plate (Item 8).

[Rich P.]

Re: More fastener questions

PAI is definitly aftermarket. The rear pinion snubber bolt is cad/zinc grade 8 Headmarking is M, TR, [] and a few others. Both large washers are cad/zinc, lock washer is black and the nut has a copper finish originally.
The 2 other bolts for the shifter bracket to frame are original bolts but not correct for this application. Original bolts have a recessed flanged head and self starting/cutting threads...headmarkings I have seen are M, D, RBW, Blank and a few more.

The front control arm to frame bolts do not have a flat washer just a lock washer. Bolts and lock washers are cad/zinc. Nut plate to frame is natural with mounting faces being freashly machined.

Rich

[Rich P.]

Re: More fastener questions

My (late) 70 AIM shows flat washers on the rear control arm mounting bolts (A4A, Item 4, Part Number 3693853). I can't find anything in my notes on finishes, but didn't Joe Lucia just tell someone the finish on the bolt and nut?

Rear control arm bolt specs are as follows (This is for mid 66-up) bolt is black phosphate, special serrated flat washer is black or natural, locking nut is cad/zincl

Rich

[Keith L.]

Re: More fastener questions

Thanks guys, now I,m doubting the bolts on the tranny mount bracket on page 6 B4. I know that one of the no. 8 bolts (454933) was longer than the other. And the 2 no.3bolts (9419073)were identical to the shorter no8. And the no. 7 bolts (9418967) have two different head marks even though they are identical. But they seemed a little long when I put them in. I can't find pics of them but I think two had LE with 3 radial lines. The other 2 just had the lines. What should be the length of those (9418967). They were silver cad.

[Keith L.]

Re: More fastener questions

Join Date: April 8th, 2008
Posts: 194


Re: More fastener questions
Are the LE headed bolts original? Center cross member through tranny mt bracket. They are 1"long. The bolts holding tranny rubber mount to bracket and to tranny are 1.25 long with an A on the head. The AIM shows two different part numbers. The nuts at tranny mt are just to hold it till tranny goes in.

[Rich P.]

Re: More fastener questions

Keith,

The LE's are incorrect. The A bolts that are 1.25" long are not correct for the center hanger. The correct bolts are 1" Long grade 5 the 1.25" bolts you have are correct for the rubber trans mount to trans, and A is a original headmarking. They should be grade 5. These 4 bolts (the 4 that attach the rubber mount to the frame and trans) are 7/16-14 thread while the 4 bolts that hold the trans bracekt and shifter bracket to the frame are 3/8-16 thread. I will post pictures of the correct bolts later tonight.

Rich

[Rich P.]

Re: More fastener questions

Kieth,

here are some pics of original bolts. first off are shots of the rear shifter mount bracket to crossmember bolts
They are 5/16-18 thread with a recessed flanged head and self cutting threads. If you look closely at the starter threads you can see the are taperd and have a step in the firs 2-3 that act as a tap.

Rich

[Rich P.]

Re: More fastener questions

Next are some headmarkings of the 4 3/8-16 thread bracket mounting bolts. C, SC, RBW and as I said there wer other headmarkings.

[Rich P.]

Re: More fastener questions

Forgot this shot.

[Keith L.]

Re: More fastener questions

Thanks Rich so much. What are the lengths of the bolts pictured?

[Chuck S.]

Re: More fastener questions

Thanks Rich so much. What are the lengths of the bolts pictured?

I show them as 7/16 NC X 1".

I have one each of two different headstamps...M with three equally spaced lines, and A with three equally spaced lines. Both of these headstamps are common on my late 70, and on other 68-72.

I disagree with Rich about the LE headstamp being "incorrect"...if I found those on my car, I would assume they were original unless there was some other evidence of tampering. My 70 had a few LE headstamp fasteners scattered around in different sizes and applications. I think the LE headstamp is correct for the period; I don't know whether they were used specifically in the transmission support application.

Edit: I also show 6B4, Item 3 (mounting cushion to transmission) as 7/16 NC X 1", both bolts with A headstamp and three equally spaced lines. The description sounds exactly the same as Item 8, but there is a different part number. Curious, I wonder if they were substituting one bolt for the other...what is your VIN Keith? (Never mind, I read in your original post that you have an early 70.)