How tight should the speedo cable 13 mm bolt at the back of the transmission be?

[Bmachine]

While doing an oil change yesterday, I noticed some oil drips at the back of the transmission. Upon further inspection, it looked like it was coming from the speedo cable entry point. I checked the 13mm bolt there and it was very loose. I started tightening it up, and it felt strangely soft as I did it. Not stripped, mind you but it felt like it was going into some thing soft. How tight is that bolt supposed to be?

 

[Ohmess]

My recollection is that the bolt fits into a groove and only needs to be tight enough to keep the cable from coming out.

I just looked at this on my 635csi barn find. Your leak is coming either from the o ring for the speedo drive, or the shaft seal inside the speedo drive unit. Replace the o-ring first. The shaft seal is small and difficult to replace.

 

[eriknetherlands]

I think the tech manual have torques for nearly all bolts. If not, look up any other similar diameter sized bolt in an Alu part

 

[Dick Steinkamp]

I checked the 13mm bolt there ...

If you used a 13mm wrench, it is likely an 8mm bolt.

 

[Bmachine]

If you used a 13mm wrench, it is likely an 8mm bolt.

Correct indeed. My point was that I am really surprised they put an M8 there if it only has to be just tight enough for the cable not to fall off.

 

[HB Chris]

It had to be thick enough to notch it.

 

[TomHom]

The screw should come with a hole. Pull a wire through the hole and fix it in a way the screw can not turn and fall off.

 

[TomHom]

For what reason ever the left screw did mot come with a hole

 

[Bmachine]

Very good info Tom. I will need to go and check if mine has a hole in it

 

[HB Chris]

I don’t think mine have ever had holes including 2002s, 2800 and e9.

 

[Ohmess]

The one on my 635csi does not have a hole. Haven't climbed under my coupe to see if that one has a hole, but I know I did not put safety wire on it when I installed it.

 

[Cornishman]

My recollection is that the bolt fits into a groove and only needs to be tight enough to keep the cable from coming out.

I just looked at this on my 635csi barn find. Your leak is coming either from the o ring for the speedo drive, or the shaft seal inside the speedo drive unit. Replace the o-ring first. The shaft seal is small and difficult to replace.

I have three transmissions, one has a hole, two don’t. If yours does not I suggest that you drill it and wire it.

The seals, O ring is thicker than normal, but easy to change, the shaft seal is a PITA, suggest that you buy two or three seals, they are easy to damage. Or, pay someone who knows what they are doing with these, it might be cheaper.

 

[deQuincey]

@Bmachine It comes with a hole, indeed, but if not in your case, just make yourself a hole in that head

 

[deQuincey]

@Bmachine


this thread. Post #58. https://e9coupe.com/forum/threads/e9-empresas-y-tribulaciones-an-epiphany.39805/page-3

 

[deQuincey]

and, yes, bolt has a hole in the head, put a wire there,

 

[Bmachine]

Thank you for all the good info. So I assume there is no torque setting since it would be extremely low…