• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Parts manual bolt code.

Share this page

J

John_Progess

Jedi Warrior
Country flag
Offline
On my Healey and MGA the official parts manual have a discription of each bolt and in the discription the last 4 numbers indicate the bolt length and diameter. The frist two numbers are the diameter in 16 ths of an inch and the last two numbers are the length in eighths of an inch. That code does not seem to apply to the TR 3 parts discription. Is there another way to tell the length and diameter from the discription? What bolt goes where is one of the issues when buying a car in parts. Thanks and have a good day?
 
There is a code for Triumph parts; but not all of the hardware is "standard". If the part number starts with two letters and has 3 or 4 digits, then it is a "standard" hardware item and you can look the description up in
https://docs.google.com/file/d/0B2H...ZTk0LTk1YTUtZTIyZmU3ZTc1Y2M4/edit?usp=sharing

But if it is a 6 digit number, then there is something special about it, like maybe the material (high tensile) or an extra-long unthreaded section. Those can be much harder to chase down; but there is something to be said for replacing them anyway since they are usually important.
 
When I get a parted car I sort the bolts by size , then I get my pick and measure how far each bolt has to go in it's particlular place. Width and threads are by sight. Engines, I throw all bolts together as they only go in certain places and it's more obvious. Usually , I go by websites and order all new bolts, especially if a restoration and not my car.
 
LarryK said:
When I get a parted car I sort the bolts by size , then I get my pick and measure how far each bolt has to go in it's particlular place. Width and threads are by sight.
Click to expand...
There are a couple of places on a TR3 where that can burn you. The problem is that they aren't all SAE threads and if you aren't paying attention, it's easy to bugger the threads before you realize that you're trying to force, for example, a 5/16-24 UNF nut onto the 5/16-22 BSF threads on the starter solenoid studs.

The weird stuff is mostly electrical and carbs; but there are some BA threads in the body as well.
 
TR3driver said:
The weird stuff is mostly electrical and carbs; but there are some BA threads in the body as well.
Click to expand...
Could be, but I'd guess that any BA or other odd threads "in the body" are most likely to be on door latches, spare tire door lock escutcheons or other odd little bits from outside suppliers (Wilmot-Breeden, Rubery Owen and the like) rather than fender bolts, body-to-chassis bolts and the like. Standard-Triumph had done a pretty good job right after the end of WWII in moving towards UNF and UNC "standardized" hardware as much as they could, part of that coming from their desire to have the Standard Vanguard be as much a "world car" as possible.
 
The BA threads I ran into on my TR3 resto were all smaller then 1/4" -- 2BA and 4BA. The other "weird" sizes were electrical and instrument.
 
Back
Top