Roadside Timing Belt Job: a how to on replacing the tb without removing the crankbolt
12-23-2010, 01:12 PM
#1
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Roadside Timing Belt Job: a how to on replacing the tb without removing the crankbolt
Had to replace my timing belt on the side of the road in the middle of Missouri. I didn't have a crank lock tool with me, but luckily it is possible to replace the belt without removing the harmonic balancer and crank bolt.
Hopefully no one else has to do so, but this may help someone out.
My experience was with a 82, and I believe this should apply to most if not all 16v cars.
Needed:
1) 10 mm wrench (tb cover bolts
2) 7/8" wrench (tensioner adjustment)
3) 1 1/16" deep socket and ratchet (to turn the crank)
4) 15 mm (?) wrench (for bolt holding tensioner pulleys)
5) Kempf tool or equivalent
Starting with the car in neutral,
1) Remove belt covers
2) Loosen tensioner with 7/8" wrench, and slip the belt of the camshaft gears
3) With the belt covers off, you should be able to wiggle the belt out from around the oil pump gear. The belt should now be hanging from the tensioner pulleys, but still wrapped around the crank gear.
4) If you look carefully (or feel) around the harmonic balancer, there are two pins of sort that come out of the block. There should be about about 3/16" of space between the end of the pins and the balancer though. This is the critical space that allows you to slip the belt through with the balancer still on.
5) There won't be normally be enough wiggle room to slip the belt out though. You need to gain a little more maneuverability - by getting the belt out from the tensioner pulleys. The pulleys pivot on a single bolt (15 mm ??) and loosening this bolt allows the pulleys to slide forward.
I believe you should be able to twist the belt out by only loosening this bolt (like you can do with the harmonic balancer off), but I found it easier to remove it entirely. If you do so though, remember to stick the bolt back in quickly so you don't drain coolant.
6) With the belt out of the tensioner pulleys, you should be able to gently twist it 90 degrees, and slip it out between the pins and the harmonic balancer. Depending on the clearances on your car, you may need to align the pins with the valleys in the belt.
7) You can then install a new belt by reversing this procedure.
(Slip by pins, Install tensioner pulleys, slide belt around oil pump and cam gears, tension belt).
With the new belt, remember to turn the crank a couple of times and tension properly.
Wrench sizes may not be entirely accurate - they're based on my memory alone.
Hopefully no one else has to do so, but this may help someone out.
My experience was with a 82, and I believe this should apply to most if not all 16v cars.
Needed:
1) 10 mm wrench (tb cover bolts
2) 7/8" wrench (tensioner adjustment)
3) 1 1/16" deep socket and ratchet (to turn the crank)
4) 15 mm (?) wrench (for bolt holding tensioner pulleys)
5) Kempf tool or equivalent
Starting with the car in neutral,
1) Remove belt covers
2) Loosen tensioner with 7/8" wrench, and slip the belt of the camshaft gears
3) With the belt covers off, you should be able to wiggle the belt out from around the oil pump gear. The belt should now be hanging from the tensioner pulleys, but still wrapped around the crank gear.
4) If you look carefully (or feel) around the harmonic balancer, there are two pins of sort that come out of the block. There should be about about 3/16" of space between the end of the pins and the balancer though. This is the critical space that allows you to slip the belt through with the balancer still on.
5) There won't be normally be enough wiggle room to slip the belt out though. You need to gain a little more maneuverability - by getting the belt out from the tensioner pulleys. The pulleys pivot on a single bolt (15 mm ??) and loosening this bolt allows the pulleys to slide forward.
I believe you should be able to twist the belt out by only loosening this bolt (like you can do with the harmonic balancer off), but I found it easier to remove it entirely. If you do so though, remember to stick the bolt back in quickly so you don't drain coolant.
6) With the belt out of the tensioner pulleys, you should be able to gently twist it 90 degrees, and slip it out between the pins and the harmonic balancer. Depending on the clearances on your car, you may need to align the pins with the valleys in the belt.
7) You can then install a new belt by reversing this procedure.
(Slip by pins, Install tensioner pulleys, slide belt around oil pump and cam gears, tension belt).
With the new belt, remember to turn the crank a couple of times and tension properly.
Wrench sizes may not be entirely accurate - they're based on my memory alone.
12-23-2010, 01:36 PM
#3
Rennlist Member
How did you get the lower cover off?
Was your little guide roller and carriage that is normally present on those pins installed beneath crank when you began?
Was your little guide roller and carriage that is normally present on those pins installed beneath crank when you began?
12-23-2010, 02:24 PM
#5
Nordschleife Master
12-23-2010, 03:59 PM
#6
The bottom part of the lower cover had been broken off my 78 Euro by a PO, so I was able to change the belt without removing the balancer. Wonder how many more 928's have this mod by previous mechanics? BTW I had to take it off about 3K miles later when the front main seal blew. 
Dennis
Dennis
12-23-2010, 04:36 PM
#7
Nordschleife Master
On the cars I've worked on, the guide piece that goes over the two studs that the OP describes captures the belt behind the harmonic damper. I found it very interesting that he describe "two pins" which should be covered by the guide except for the tips.
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12-23-2010, 04:58 PM
#8
Rennlist Member
Wow, quite a roadside repair. What part of mid Missouri where you stranded in? If it ever happens again, I have a basic garage and flywheel lock tool from my recent TB job.
12-23-2010, 05:38 PM
#9
Various parts of my belt covers are gone, too.
On the cars I've worked on, the guide piece that goes over the two studs that the OP describes captures the belt behind the harmonic damper. I found it very interesting that he describe "two pins" which should be covered by the guide except for the tips.
On the cars I've worked on, the guide piece that goes over the two studs that the OP describes captures the belt behind the harmonic damper. I found it very interesting that he describe "two pins" which should be covered by the guide except for the tips.
Dennis
