Archived Setting timing on a 12-v: Gear keeps slipping - Help!

[JGK]

I have an early '98 12-valve with the 215 pump. A bud and I tried to set the timing on mine today. We have the Snap-On timing kit and successfully re-timed his auto (180 pump) last week. His is holding great but mine will not hold. The gear keeps slipping. We've used the same procedure in both cases: set the desired lift, pulled the gear, reset TDC, then hose the crap out of the shaft and gear area with brake cleaner and torque down the nut. However, the gear keeps slipping on mine. We even torqued it to 170 ft-lbs. But we can get it to slip just flicking the throttle as it idles in the garage.



What is the secret to getting the gear to stay put? I need some input from someone who has done this multiple times with success. I don't even want to talk about pulling the pump The only things we haven't tried is blowing out the area with compressed air before and after using the brake cleaner and using any sort of Loctite. I've search the forums and saw a few ideas, but nothing definite from any one with a lot of experience that I could find.



We've given up for the night. A call will go out to Piers in the morning. We'll give it another go tomorrow evening.



BTW: this same post will be put in the 12-valve forum.



Thanks in advance. Happy New Year!



-Jay

 

[Bill Lins]

I read somewhere that putting a couple of chalk stripes on the taper before mounting the gear will keep it from slipping. Of course, cleaning it well with brake cleaner first is necessary. Good luck.

 

[Blair]

Are you sure your torque wrench is accurate? Did you install a new lock washer? Make sure you blow it out with compressed air after you spray it with brake clean. Most brands of brake clean leave a residue so make sure yours doesn't or use electrical contact cleaner.

 

[cmonroe]

Having had the same problem before I can tell you to get the shaft surface and the inside surface of the gear clean. Then take about 220 grit sandpaper and ruff up the mating surfaces. Also ensure the gear is not egg shaped.

 

[chrleb1]

There are a couple of other ways also... . One would be to clean the shaft very well then apply locktite to the shaft and then tighten. Make sure you wait for a while after you have it back together. This will ensure that the locktite sets up. Then another way, and this would be for some of the serious HP guys, is to make sure you have your timing set exactly where you want it and then drip and tap the shaft and gear together. So basically you will have a set screw and the gear will not be able to slip at all.

 

[R.E. Miller]

Where I work, it is the same routine as stated above. Of course i have a little twist, when the pump is out, I use as much brake cleaner as it takes to clean and blow out the gear, hole, and injection pump alway followed by air. Then the torque that is considered standard now is 195 ft/lbs> sounds like a lot, but you of all people can understand why. Finally, I use CRC contact cleaner followed with air treatment before I go to torque the nut.

Hope this helps,

Russell

 

[Jim Fulmer]

Do a search on the 12V form and 911 forms, this very same thing happened 3-4 weeks ago, there solution was to slightly T/Q the nut for the final lift check... ... I have to agree with the contact cleaner on this one.



Jim