Sanity Check - Oil Pump Chain Tension

[JsnPpp]

I pulled the pan, removed the nut and measured. 7.9mm

 

 

The washer is in place and the gear is straight.

 

Thread depth is 7.3mm. So, good catch on this that it's 0.6mm wider than the threads.

 

 

 I do like the thinner nut listed. I did check and 07119901301 appears to be available, part 18.

 

I don't see where 07129922436 is listed as a replacement but it is a locknut.

 

SO, long/short. I don't mind waiting another week if I choose to orderf the nut but I'm trying to decide if it would make a difference. Slightly wider + red loctite is the same to my mind as slightly thinner + red loctite.

 

Is it agreed that 45NM (~35 ft-lbs). Does this feel ok to the group? 

 

As a data point, here is the pump before I pulled it and a movie for the original slack. It's the same nut that ran for 12 years + 60K miles. Not saying that makes it ok but it's a data point.

 

https://youtube.com/shorts/-3hXdzUPP2c?feature=share

Edited February 25 by JsnPpp

[tech71]

50 minutes ago, JsnPpp said:

 

SO, long/short. I don't mind waiting another week if I choose to orderf the nut but I'm trying to decide if it would make a difference.

I think you are good to go with that nut, it looks like the OE one, sorry, it looked to fat in the first pic.

Might as well use red locktite this time😁

 

[Henning]

13 hours ago, JsnPpp said:

 

This is too strong in my eyes. When I did it like this, my chain took off. There has to be some slight slack I think.

 

henn

 

[JsnPpp]

9 hours ago, tech71 said:

I think you are good to go with that nut, it looks like the OE one, sorry, it looked to fat in the first pic.

Might as well use red locktite this time😁

 

 

 

No sorries needed! I asked for sanity check and appreciate the time you spent on this. I don't love redoing things but I'm used to it, ha ha. Better to be safe and double check, it's 100K times easier to fix now than when the motor is back in the car. I'll switch to red loctite.

 

The youtube link wouldn't embed for me last night for whatever reason.

 

I'm going to use ~35 ft lbs. Here is the best link I can find on this topic: 

 

 

[TobyB]

Since that nut didn't exist on the car during (or even for decades after) its manufacture, there won't be an

original torque for it.  I don't remember when it eventually showed up- E36 era, maybe?

One of the dumber- of many- BMW cost- saving measures.

 

If I was a person who regularly used a torque wrench, I'd find the earliest stated BMW torque

and use that.  35 ft- lbs seems to be in the right ballpark.

 

t

still uses blue loctite, but

also uses sleeve retainer.

 

[JsnPpp]

Thanks folks. I did switch to red loctite and squeaked it up to 40 ft lbs torque. 

 

Jason

[kbmb02]

5 hours ago, JsnPpp said:

Thanks folks. I did switch to red loctite and squeaked it up to 40 ft lbs torque. 

 

Jason

 

Perhaps worth noting (on the late side, perhaps) that not all “red loctite” is the same… for example, some types  of red loctite are suggested (rated?) for combination of heat + oil resistance, others, not-so-much. -KB

 

[JsnPpp]

2 hours ago, kbmb02 said:

 

Perhaps worth noting (on the late side, perhaps) that not all “red loctite” is the same… for example, some types  of red loctite are suggested (rated?) for combination of heat + oil resistance, others, not-so-much. -KB

 

 

Appreciate that, good call. I used Permatex Red 27100 which described as heat and vibration resistent + is permanent (may require special tools).

 

Says it's good for rocker arm studs, etc. transmissions...

 

I'm actually now more concerned if I ever have to get the dang thing off! 

 

It feels like it's ok, but if anyone has had bad experience with 27100 then please let me know..

 

Jason

[Einspritz]

Not to be cranky, but I'd still like to know if anyone has actually, personally seen that nut remove itself from an original engine or quality builder.