Correcting IP sprocket alignment?

tim0574 · Post by **tim0574** » Tue Aug 14, 2007 3:20 am

I have a 82 diesel pickup with a rebuilt motor I plan to sell soon but I noticed the timing belt is running wide on the IP sprocket and chipping away the belt on the intermediate pulley edge guide. It seems to hang off the sprocket 1 mm or two.

I've only seen the problem referenced a few times and the blame is usually the bushing though I'm not seeing any fuel leakage. How do I correct the condition without replacing the pump?

I backed off the belt tension a bit but got a nasty belt vibration coming off the crankshaft. Tightening it back up corrected that.

Would slipping a washer between the pump and the bracket at the frontmost hole do the trick?

coke · Post by **coke** » Tue Aug 14, 2007 7:00 am

Sometimes its the alignment of the pump on the IP bracket itself. Or the IP bracket gets bent some. I would fiddle with the pump it self and try different alignments. On my 90 Jetta, it was as simple as pushing the back end of the pump down (Side closest the head) Sometimes, it requires more complex procedures.

If its truly the shaft bushing, then you'd have to shim the pump up somewhere to draw the belt back in.

Someone told me the cardinal rule to remember is the belt always tracks the point at which it contacts the pulley first.

3Bunnys · Post by **3Bunnys** » Tue Aug 14, 2007 8:33 am

I also have a belt that doesn't track well...Lets say its marginal, I replaced front bushing during reseal job...did not help one bit...
I keep reading about shimming pump, but I really don't see how this will work ..... Problem, if you shim front of pump, rear pump bolt won't line up..
LQQks to me as if you would have to remove entire pump bracket and shim..... Maybe I should just steal an entire bracket off a dead bunny and use !!!!!
BTW... I laid a long machinist straight edge across face of cam and IP sprocket and they are not close to parallel..
I hope to see some good technical responses to this problem !!!!!

And I would really prefer not having to disassemble half the engine to correct

Regards Richard

PS...this is the reason I remove and do not reinstall upper belt guards on my Bunnys,,, When I check oil I want to be able to eyeball timing belt.............

coke · Post by **coke** » Tue Aug 14, 2007 8:40 am

Sounds to me like your IP bracket may be bent some, 3Bunnys.

Its tricky and I figured out my own problem quite by accident when I was timing my engine by ear. I said, "Whoa. Its fixed. Amazing"

3Bunnys · Post by **3Bunnys** » Tue Aug 14, 2007 9:06 am

Can't say I particularly looked for bent sprocket, but think I would notice a wooble due to run out while engine is running,,,, But I will eyeball within the next 24 hrs, might even put a dial indicator on it and report back,,, Thanx for the idea...

Richard

Gearhead · Post by **Gearhead** » Tue Aug 14, 2007 9:13 pm

I think he said bracket. If it's bent, the pump will be a little "cocked"

tim0574 · Post by **tim0574** » Wed Aug 15, 2007 2:30 am

One of our local car lots had a red diesel pickup show up that I stopped and looked at. I was looking it over even though they said they are holding it since it needs welding and they may sell it on eBay blah blah blah.

Anyway, I was looking under the hood and noticed there was a brace type bracket from the IP bracket and connected at a 45 degree angle to the top of the alternator bracket. I don't think either of my diesels have this little piece.

Does this piece have the ability to pull the bracket in a bit?

3Bunnys · Post by **3Bunnys** » Wed Aug 15, 2007 7:30 am

Yes he did write Bent Bracket.... Guess I can't read!!!!

I have considered smacking bracket with a hammer..the tool of last resort !!! but I will throw this question out again...

If you knock that front bracket around, the one with 3 mounting holes, the hidden 4th bolt at the back of the pump won't line up!!!!

Just checked my photo collection,,, one of these days I will get some posted,,, rear mounting bracket is stamped steel, with two bolts holding to block and two bolts clamping to front mounting bracket; front monting bracket is also stamped and appears to have two allen head bolts into front of engine....

So who out there has successful shimmed or bent or whatever, then bolted IP back on using all 4 mounting bolts and corrected problem..!!!!

Maybe I will seek help from the Blond, she has a diffferent way of looking at things!!!! Richard

tim0574 · Post by **tim0574** » Fri Aug 17, 2007 2:33 am

I don't want to disassemble anything since I don't want to monkey with the perfect timing. I tried snagging the bracket with a flare wrench that I could put a bar on and give a little bend. When I hand cranked the engine, the belt seemed to be wandering again.

I ran into another problem so I haven't gotten back to giving another go to the flare wrench method. There's also a thread hole I can tried to bolt something strong to and use for leverage.

When I straight edged the sprockets, they were very close. but not quite parallel.

A1-2-A3 · Post by **A1-2-A3** » Fri Aug 17, 2007 9:20 am

Hmm, how about remove the rear bracket off the engine behind the
IP and slot the hole that bolts to the IP rear bracket. Then you would be able to bend the front IP bracket to align the belt then tighten the rear bolt. Easy as 123.

Also R and I the IP and retime, weee. FUN!

3Bunnys · Post by **3Bunnys** » Fri Aug 17, 2007 10:21 am

Well the rear mounting bracket is an interesting creature.... I've never studied it really closely but it appears to be a rubber insert into the bracket with a metal center piece...... The nut you use for this end of the pump is cone shaped on the outside, almost like a flare nut for tubing, and goes into a matching hole in the bracket...... (self centering,,,so to speak).... so you would probably end up modifying the end bracket on pump, which is already slotted in such a way as to allow timing rotation of pump....

Richard

A1-2-A3 · Post by **A1-2-A3** » Fri Aug 17, 2007 12:16 pm

Or you could grind the surface of the bracket to angle it to the block mating surface to correct alignment(which would be somewhat time consuming and trial and error like.

Krank · Post by **Krank** » Fri Aug 17, 2007 3:38 pm

IMHO, you guys are going WAY too deep to find the solution! I found this problem when I was building my engine and had it on the stand.
The hidden IP bolt connects to a bracket that bolts to the front of your block. If you loosen this bracket from the block, you can push or pull the IP bracket just a little in either direction. With pressure applied the correct direction, re-torque the bracket back into place. I found that loosening the IP bracket before tightening the 'hidden bolt' bracket allowed even a greater degree of flexibility.
It's not a bent bracket... it's just made to be a bit adjustable is all!
Enjoy, and tell me wonderfull stories of your success!

tim0574 · Post by **tim0574** » Tue Aug 21, 2007 12:53 am

I did some comparing between my pickup and my hatchback. There are 3 less bracket pieces on the pickup (which is giving me alignment trouble) than the hatchback.

The hatchback has a bracket coming off the alternator bracket. It also has a beefy bracket on the block behind the IP that is completely missing from the pickup. And lastly, there is a dainty little snubby wishbone sort of thing that appears to go from the back IP bolt to the bottom IP bolt.

I could simply have a problem with the choice of washers they used to gap and make up for the lack of brackets not put back on after the rebuild. The washers are thick though the one in the front looks less so compared to the back and bottom washers.

No nevermind, the washers are at the head of the IP bolts, not anywhere that would affect alignment.