overtightened belt VS. premature IP bushing failure - page 1 - IDI Engine - VWDiesel.net The IDI, TDI, and mTDI source.

• overtightened belt VS. premature IP bushing failure by rabbitman on 09 Oct, 2007 15:03
• Hello, I'm having a problem, I sent my IP in because the bushing is worn and the rebuild shop is trying to charge me $175 to do it. I bought the pump in March of '07 from Midwest Fuel Injection in Illinois, drove 12,000 miles and it's junk and within' 5,000 miles the timing belt was starting to run off center. It is warranteed for one year from date of purchase so I thought they would do it for free but they're trying to say it's my fault because I didn't use a belt tensioner gauge, who on earth uses a gauge? Also, the company told me that it's nessessary to completely disassemble the Injector Pump to change the bushing, is that true? Should I pay or complain some more?  Sorry 'bout the earfull, any advise or information will be appreciated.
• #1 by Vincent Waldon on 09 Oct, 2007 15:13
• Unfortunately the answer to both your questions is yes:
  
  YES it is necessary  to completely disassemble the pump to replace the bushing, and YES if you over tighten the belt by not using the official gauge the bushing will wear in very short order.  And your IM bearings, too, unfortunately... causing oil pressure problems in the near future.
  
  Replacement bushings require custom reaming so there's some labour involved once the pump is gutted.
  
  On the A3 diesels and up VW *only* publishes the official tension gauge spec... no more "an approximate measure" line in the service manual.
  
  
  
  Vince
• #2 by myke_w on 09 Oct, 2007 19:52
• A rule of thumb is that you should be able to turn it 45 degrees without excess force, for gassers it's 90 degrees
• #3 by Quantum TD on 09 Oct, 2007 23:07
• On a side note: the belt running off center concerns me a bit. Even with an overtightened belt, you probably should not see runout. Is it possible that your IP mouting bracket is bent? Something to maybe look into.
  
  As far as the premature IP bushing failure: I must concur with the other posters. You really don't have a pot to piss in on this matter with the reman company. Had you used a proper gauge, then you could refer to that. But, you're SOL in terms of an argument, despite the fact that another problem (a bent IP bracket: again your own problem) may have been the proximate cause of the premature busing failure.
• #4 by myke_w on 10 Oct, 2007 06:08
• I've seen worn pumps run off center, I had one running off the edge of the drive pulleys in the shop last year, put a rebuilt pump on it, straightened right up.
• #5 by saurkraut on 10 Oct, 2007 08:53
• Quote from: "libbybapa"

  Yup, those who frequent my ranting know that's a soapbox I like to shout from.  Don't over-tighten the belt.
  
  Andrew

  
  
  So sayeth the sheppard, so sayeth the flock!
  
  I'd like those who have found this phenom of bent brackets to be the cause, to detail the cause of the bent bracket.
  
  I suspect that these engines are swaps from wrecks, or the engine was miss-handled while out.
  
  I've putzed with alot of these, and have never seen a bent pump bracket.  And, I would suspect that its virtually impossible to bend the bracket in normal use.  Pulling an engine from a wadded up car is more likely the culprit
• #6 by myke_w on 10 Oct, 2007 09:06
• we suspected a bent bracket once, we were wrong.. man, that thing is so thick, you'd have to heat it to bend it in the vice, it' also has that curved edge which adds a boatload of strength, show me a bent bracket from normal use, I'll show you a flying pig (or a flying vanagon maybe)
• #7 by rabbitman on 10 Oct, 2007 11:06
• yeah, another thing is that they have my pump now so there isn't anything I can do. I thought the IM bearings were the main concern when the belt is to tight but I can't feal any slop in them.
  
  Do all of you guys use a tensioning gauge?
  
  The guys at the shop I was working at when I installed the IP said they never use a gauge on rabbits and they've been in business since '87. They rarely get rabbits in there anymore though, it's mainly newer jettas passats and A4, A6, A8s
  Oh well, I'll stop whining I guess :cry: Thanks for the help guys
• #8 by myke_w on 10 Oct, 2007 11:35
• if the ip warrantee place asks me if i used a guage, I'd say I used a guage, but if you ask me, I'd tell you to make sure it will turn 45 degrees of center with moderate pressure.
  
  The guy who taught me vw's used the gauge and found that once set, the belt turns about 45 degrees, same thing right?
• #9 by Black Smokin' Diesel on 10 Oct, 2007 13:06
• I never used a gauge, 45 degrees for me. As for the belt walking on the pulleys, there are several causes for this: Worn bearings, bent bracket, bent tensionner stud, crooked pulley, work crank nose... I had a walking belt when I replaced the head on my 1.6td. Turns out the injection pump pulley wasn't installed straight. Loosened it, re-tightened and voila.
  
  You might want to consider replacing the intermediate shaft pulley if yours has guides on it. The belt is so tight that if it walks too much the IM pulley will cut through it. The later 1.6 and 1.9 IM pulleys don't have these guides. I replaced mine (87 td) when I saw what was going on.
• #10 by rabbitman on 10 Oct, 2007 16:58
• I never knew it was possible to put the IP pulley on wrong. My IM pulley is the kind without guides.
  Anyways the rebuild shop knocked the price down to $95 so I payed it, I didn't have a choice anyhow. I hope they use a better bushing or something 'cause I'm sure the belt wasn't to tight. Oh well, it'll be here in a few days at least, I haven't driven it in almost a month so I can hardly wait I've been borrowing cars or driving my subaru which is not supposed to be on the road so I drive it like a granny :roll:  Thanks for the help.
• #11 by saurkraut on 11 Oct, 2007 05:22
• How in the heck do you bend a tensioner stud?  Same thing with the pump bracket?  They are very stout pieces.
  
  These discreapancies have to be from an engine pulled from a wreck.  Why would anyone install an engine that was obviosly wacked on the timing belt side with out checking it first?
• #12 by saurkraut on 11 Oct, 2007 08:09
• Huh, never had that problem on the ones i've put to gather.  I usally put in all the bolts loose and sort of cross torque them till tight.
  
  I guess there is a first time for every thing....
• #13 by rabbitman on 23 Oct, 2007 11:57
• I finally got my IP back from the rebuild shop     . Now I just have to put it on :roll:
• #14 by rabbitman on 23 Oct, 2007 18:57
• :oops: hi......um, I messed up. In my futile efforts to get the cam gear off, which consisted of hitting it repeatedly with a hammer :oops: I managed to bust the end of the shaft off :x now I have to order another one. I've taken the gear off many times and it was never a problem. I loosened the bolt but left it real close to the gear so the alignment would stay the same, I must have left it to close. bugs me that I could be so stupid :cry: