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gearbox steady cable bolts
Posted: Wed Dec 17, 2008 9:37 pm
by picky
cant find my haynes manual, i fear i have two stripped threads in the gearbox casing, where the bolts hold that small metal bracket that the steady cable connects to. what is the correct bolt size? just so I know im fitting the right bolts. cant see properly if the threads are damaged or not as the gearbox is in the car.
Picky
Posted: Wed Dec 17, 2008 9:42 pm
by Matt
cant remember the thread size, but 99% sure they are 7/16th spanner size
If they are stripped you could carefully helicoil them in situ?
Posted: Wed Dec 17, 2008 9:59 pm
by picky
hopefully i am just trying the wrong bolts... will find some that are 7/16th and give it a go. at the moment i am using some that screw in a bit and then slip, but they look fairly new so they might be metric.
Picky
Posted: Wed Dec 17, 2008 10:01 pm
by alex_holden
I think they are a coarse pitch - maybe UNC.
Posted: Wed Dec 17, 2008 10:13 pm
by rayofleamington
Sorry to pre-judge this but I bet you've stripped them. The threads are pretty weak (I've wrecked a couple myself).
The butcher's alternative to helicoiling them is to take a length of M8 all-thread from the bell housing/engine joint to the start of the cable - then weld the cable braket to the end of the all thread. I'm speaking from experience that it's a workable solution
Posted: Wed Dec 17, 2008 10:26 pm
by picky
no offence taken ray, it is quite possible. i would prefer to redo the threads, a bit of a neater solution
i have some metric(!) taps so I could tap a slightly bigger thread and fit a metric bolt. im going to have to remove the gearbox support to get a straight line though... some jobs just take 10 times longer that u think dont they?? would hope that i can find a bolt that screws in as is.
Picky
Posted: Wed Dec 17, 2008 10:56 pm
by bmcecosse
I would just tap them out next metric size up.
Posted: Thu Dec 18, 2008 9:47 am
by rayofleamington
i have some metric(!) taps so I could tap a slightly bigger thread and fit a metric bolt
that's probably the answer then (unless you're really lucky)
Posted: Thu Dec 18, 2008 1:06 pm
by jaekl
For the record the bolts are 1/4-28 (UNF). Also those three are longer than the rest.
Posted: Thu Dec 18, 2008 7:34 pm
by bmcecosse
Surprised at the fine UNF thread in alloy - that's probably why they have stripped!
Posted: Thu Dec 18, 2008 8:35 pm
by rayofleamington
Surporised at the fine UNF thread in alloy - that's probably why they have stripped
as mentioned already - the threads are pretty weak.
A fine thread in a casting is a bit odd, but at least they don't need to be touched very often.
Posted: Fri Dec 19, 2008 12:43 am
by picky
right are all three bolts the same thread? I have one bolt that will tighten up well in one of the threads, but slips when put in either of the others. looks like I will be tapping them metric.
Picky
Posted: Fri Dec 19, 2008 12:02 pm
by bmcecosse
Sounds like the threads are stripped out in the alloy - tap away!
Posted: Fri Dec 19, 2008 12:33 pm
by picky
interestingly one of the holes in the metal bracket was slightly bigger than the other two. This suggests to me there are not all the same thread in the casting. Anyway, ive tapped the two iffy ones out to 8mm and its now all tightened up ok
Posted: Sat Dec 20, 2008 10:36 am
by rayofleamington
right are all three bolts the same thread?
originally they were all the same thread.