OK, so I got the Wide band O2 sencer hooked up today and took the Pangra for a spin. Got it warmed up and then got on the freeway. Did some good boosted pulls on the freeway ( about 10-15 lbs boost). I had just got done with a little on the boost run and was decelerating back down to 65 mph when I put my foot back on the gas and there was nothing, no power no motor ?????. Got it down an off ramp , opened the hood and saw the timing belt was off the cam pulley??? weird, I've never thrown a timing belt before. The belt had about 50 miles on it and other than a chunk where it tore slipping off there was no other signs of a problem. Any one have this happen to them and if so, what was the cause?
I've never actually had a motor throw a good T-belt. My guess would be to look VERY closely at your idler pulley. If it's not square it will run the belt off. Actually any non square pulley would do it, but considering the other 3 are bolted to shafts, this is the most likely.
TurboPinto72,
50 miles is enough for a belt to stretch out from being in the box. You did not say what your decelation rpm was when you put your foot to the gas. Assuming you know what you are doing and I think you do I suggest your belt went airborn. Considering the g forces plus the tug stretch the belt experienced a pulse that took it airborn for just a fraction of a milli-sec. The belt thought that was a good time to escape this badass turbo engine....but it couldn't pull it's bottom off of the crank pulley cause there is no room. If you look closely you might see some chaffing on some teeth close by the chunck absence. the chunk was probably where it caught back into mesh but was to far out of it's grip range...and...goodbye. I think it needed tightened a tad or more.
High_Horse
Hey turbopinto72,
As long as everything is corrret as far as your pullys being in the right place and the corredt dirtection???
I agree with HH
Timing belts don't stretch.
If you were able to "SEE" the belt I assume that there was no cover over it. I would look for evidence of forigen object damage. It could have been damaged for a while.
Bill
Quote from: 77turbopinto on April 06, 2008, 01:36:43 AM
Timing belts don't stretch.
If you were able to "SEE" the belt I assume that there was no cover over it. I would look for evidence of forigen object damage. It could have been damaged for a while.
Bill
Hey Bill,
Maybe NEW timing belts do not stretch but they need to be re-tightened after about 50-100 miles.
From Pintony
Quote from: Pintony on April 06, 2008, 01:59:18 AM
Hey Bill,
Maybe NEW timing belts do not stretch but they need to be re-tightened after about 50-100 miles.
From Pintony
i think that the tensioner should have taken care of that. But, anything is possible.
I had one come off a friends '71 a couple of times while running at a SCCA Solo event. I thought,at first, that perhaps he had forgoten to install the (can't think of the proper name for this part) retainer(?) to the outside of the crank gear. It was in place though. It came off both times under hard deceleration into a turn (all the way out of the throttle) and they are very difficult to reinstall without removing the pulley.
Anyway, we got it back on and turned out another 15 or 20 laps that day with no other problems than a few spins at the last turn (a 180 degree hairpin out of a 45 degree left hander decelerating from about 60 mph to about 15 mph before entering a the long front straight)
I think the guys are right. It probably was the sudden release of 'pull' on the belt that
simulated a 'stretched' condition that allowed enough of a release of tension that it 'walked' itself off the pulley.
Quote from: srt on April 06, 2008, 03:36:41 AM
i think that the tensioner should have taken care of that. But, anyhting is possible.
The 2.0 has a fixed tensioner it is not spring loaded after the 13mm bolt is tightened..
From Pintony
Same with the 2.3: once the bolts are tight the spring does nothing.
I did research on timing belts a long time ago (when I got my first GoldWing in 1985) and all the documentation I found (wish I still had) stated that belts don't stretch that would ever make any difference in timing or adjustment. I have changed belts that had up to 100K on them and have never found a 'loose' one other than on a Honda GoldWing. The Clymer book has incorrect information on how to set the left belt; this is something I noticed the first time I did belts on one of mine and never did it wrong. Sense then, I have changed belts on a BUNCH of them for friends of mine, as well as on cars, and I always check the tension before removal of the old one and I have never found a 'loose' belt that was properly installed. I have never had to 're-adjust' a new belt on anything nor have I ever seen maintenance instructions that indicated the need for it on fixed adustment belts, but I have never worked on a 2.0 either.
Bill
Quote from: Pintony on April 06, 2008, 08:30:44 AM
The 2.0 has a fixed tensioner it is not spring loaded after the 13mm bolt is tightened..
From Pintony
You're right. I had forgotten about that bolt back in there.
TurboPinto72,
Well..........Hmmmm....Have you checked your auxilary shaft???
High_Horse
Well, I think I figured it out. I think H H was the winner. It would seem that if your Aux shaft is frozen it causes all kinds of problems . >:( >:(
After replacing the ( first belt) and hearing the tel tale sound of the teeth being striped off at the crank, I set out to replace the belt again. You ask, didn't you have to align the distributor. The ironic thing is, it failed exactally on the # 1 cly mark on the dist so, I thought ( don't do this at home) cool, I don't have to mess with that. >:( >:( >:(.
Any way, after the second belt shredded. I figured sum thing was up. >:( >:( >:( >:(
pulled off the belt and tried to turn the aux pulley ( no turny ), pulled the dist and hand turned the dist drive to see if the oil pump had failed ( nope ). however the aux shaft is like welded in and not turning. >:( >:( >:( >:( >:(. So, Boys and Girls, how much fun do I have now......... >:( >:( >:( >:( >:( >:(. Oh and its only 12 more days until the Knotts show.......... :mad: :mad:......................................... :'(
Are those roller bearings, or slip bearings like the cam?
I've never had the aux shaft out. I had an oil pump sieze & strip the disty gear though.
You may need a 1/2" socket & a big ole breaker bar. You're gonna hafta "unstick" it to get it out!
He, he , he...... ;D I gots the big ole breaker bars..............
Sounds like the bearings have galled and siezed the shaft. I thinkl I remember you posting problems with oil pressure when you first got it running. It is possible that you hurt the cam bearings as well. :( There are two bearings that look just like cam bearings for the shaft. I never had an aux shaft seize, when I raced 2.3's, the main problem was stripping the dist gear at high RPM. Esslinger and Walsh make a bronze gear and billit shaft but they are pricey. I just used the bronze gear and made shims to eliminate the up and down movement of the dist shaft. That is the main cause of the gear failure. They will tell you that the bronze gear will wear quickly on a stock shaft but I ran mine six years w/o a problem, turned that engine 8200. Anyway, look closely at the bearings, if they are damaged you may want to pop the cam out and check those too. :hypno:
Quote from: 71 pintoracer on April 08, 2008, 03:30:30 AM
Sounds like the bearings have galled and siezed the shaft. I thinkl I remember you posting problems with oil pressure when you first got it running. It is possible that you hurt the cam bearings as well. :( There are two bearings that look just like cam bearings for the shaft. I never had an aux shaft seize,
There is only 1 bearing for the Aux. shaft on the 2.0 engine.
The rear of the aux. shaft rides in the block.
From Pintony
OOOPS! The Pangra is a 2.0 isn't it!! OK, never mind the second part of that post because I've never had problems with the 2.0 dist gear. Go back to the first part-galled bearing.
:police:
^
(Pintony-Pinto cop) :-* :-*
So, I put a 1/2 breaker bar on the Aux shaft and couldn't budge it. I thought I was going to snap the bolt off in the Aux shaft. Any good ideas I can try next ?????
PB Blaster? Seafoam DeepCreep?
Find a way to turn it the opposite direction, maybe by the sprocket?
Quote from: turbopinto72 on April 08, 2008, 09:59:52 PM
So, I put a 1/2 breaker bar on the Aux shaft and couldn't budge it. I thought I was going to snap the bolt off in the Aux shaft. Any good ideas I can try next ?????
Were you turning the bolt the correct direction?
The bolt should be loosened in a upward motion from the inner fender towards the engine block if turning from the top, under the hood.
The tightness of the bolt does not make sence??
I wonder if the 2 retaining screws to the retaining plate got loose and are all knarled up under the cover???
From pintony
Tony, I was using the bolt to try and turn the shaft. The only way to turn the shaft with the bolt is in the clock ways rotation i.e. tightening the bolt. However that did not turn the shaft. I might try and weld a 4 ft bar on a junk pulley and install the pulley over the shaft so I can utilize the key way and the bolt.
Hey Brad,
I like your idea!
Be sure to put plenty of padding on the body so you don't ding your Beautiful Pangra!!!
From Pintony
I had a 78 Pinto with a cam that would not budge. I welded the correct sized bolt to a home made adapter to my slide hammer. The third bearing pulled out with the cam. Once I got it loose I removed the bearing off the cam, removed the cam and polished it, installed a new bearing, and put it all back together.
I don't know how the 2.0 aux. shaft goes in, but maybe a similar idea could work?
Bill