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08/04/2003 18:45:54   allan   I have just bought my first 96, after a great start 120 miles or so i heard a brief knocking sound and the engine temperature went up.I stopped and had a look at the engine (while still running) and none of the pulleys were turning.I have not yet sourced a manual and have little or no idea what has happened. Can any one help a newcomer .  
08/04/2003 20:25:02   ian   Hi Allan,
From what you've written it sounds as if your balance shaft gear has stripped itself. I imagine that you'll find that all the pulleys rotate freely if you pull on the fanbelt. The downside is that it's an engine out job to replace it and you'll probably find that the plain metal bearings on the balance shaft are toast as well. If you're really unlucky the balance shaft might be knackered as well. On the plus side, it is a relatively straight forward job that can be done by a competant home mechanic.
My pet theory on this failure is that its down to a combination of old age and an overtightened fanbelt.
Good luck,
Ian
 
08/04/2003 20:45:19   jake   might be an idea to source a secondhand engine to drop in when your original is on the bench then the presure is of and you can take your time with the job i'm shure the rate at which the cars are going to the scrapyard ther's bound to be a few of them near you asumming your in the uk look at the adds page if you strip the engine on the bench keep a photo or vidio record of the dimantling then if it is some time distant before you rebuild then you can refresh your memory on where every thing went and in what order all the very best ,jake. ps it was just plain bad luck and i hope it dos'nt put you off these very rewarding and fun cars  
09/04/2003 00:08:57   Alistair Philpott   Definitely the balance shift gear this.

If you don't have the gear/time/funds etc and you can handle a bit of a bodge job with minor oil leaks after, it doesn't have to be engine out (I did it once on a North London side street with minimal tools & no lifting gear...). Here's what you do.

Remove grille & rad to gain access to the front of the engine. Remove all of the sump screws except those at the rear of the block. Remove the front cover. Take a long screwdriver & GENTLY lever the front of the sump down to gain access to the balance shaft gear, then remove & replace the gear. Refit with as much instant gasket as possible along the sump (you may need to scrape away some of the old cork gasket to get a chance of a seal). Pray it doesn't leak too much.

However, the reason it went in the first place is either the fan belt had been over tightened (as previous post) and/or the balance shaft bearings are worn allowing lateral play in the shaft. This is highly probable. This wear puts undue stress on the fibre teeth of the balance shaft gear & causes them to strip as the crank gear is steel & this chews up the fibre if they don't mesh properly. If you replace in these circumstances, the same thing will happen again soon enough.

To test, grab the pulley & move up/down & side to side. Anything more than very slight (barely noticeable) movement means the bearings are shot. That IS an engine out job, though fairly simple. Best answer is to replace the fibre gear with a steel or alloy one if you can source...  
09/04/2003 08:49:28   Alec   As stated the usual cause of this is the balance shaft bearing being worn. this generally happens because of infrequent oil changes or the use of a non-SAAB oil filter without a non-return valve in it.

Always use good Oil (10W40 in the UK)
Always use a genuine SAAB oil filter
Always change the oil every 6000 miles.

As far as the fan bely goes I don't actually agree with that. If this is too tight it will just kill your alternator bearings.
 
10/04/2003 13:02:21   tom   Alec just a quick question, are genuine SAAB oil filter's available from most saab branches?  
10/04/2003 17:32:41   ian   Alec,
My observation is based on several balance shafts that I've replaced where the rear bearing has disintegrated although the front bearing appears to be a reasonable condition. If you think of the balance shaft as being a lever you can see that any undue/uneven pressure on the front pulley/bearing is greatly magnified by the length of the shaft by the time it reaches the rear bearing. I think this is particularly true of older engines where there is likely to be more wear in the front bearing than you would find in a rebuilt or low mileage engine.

One particular instance that stands out from the others (I've had a few balance shaft gears/bearings go on me) was with a low mileage, one-owner car with FSH that had been fitted with a Kenlowe fan. The guy responsible for installng the fan had fitted a very tight fanbelt (one that was far too short for the job). When the balance shaft gear went, the rear bearing was completely trashed, but the alternator and waterpump bearings were fine.

Obviously an overtight fan belt isn't the only reason that the balance shaft bearings and gears fail but it doesn't do any harm to reduce the risk if you make sure that your fan belt tension isn't too tight.

I wholeheartedly share your sentiments regarding oil changes, filters and quality of oil.

Tom,
You'll probably find that you can only get the narrow diameter Saab filter rather than the much bulkier filter originally fitted to the V4. I've not experienced any problems with the narrow filter.

Cheers,
Ian
 
10/04/2003 18:11:46   louis   Just a word about this one: definately go for the alloy gear (never seen steal ones?). Some people say it is more noisy but for my car it was the opposite! Mine bust at about 110'000 km (don't know miles on the continent!)  
10/04/2003 18:19:20   louis   Can't help myself, but Saab filters (at least where I live) are expensive. What is inportant is that the filter contains a valve that stops it from draining when the engine is stopped this helps oil get round the engine sooner on cold start... Cheaper other makes of filter (that have a valve) are available  
10/04/2003 18:22:15   louis   You are right Alec about the belt tension nothing to do with the fibre gear as the belt is driven by the crank and the crank also drives the fibre gear but they are not connected in any way...  
10/04/2003 18:29:30   louis   Ooops! I just prooved myself wrong! The balance shaft drives the pulleys... Strange though that originally my car only had the cam gear in fibre, the balance shaft was alloy! Strange...  
10/04/2003 20:09:47   ian   Louis,
There's usually a guy at the Steam n'Spares do who sells original (narrow - smaller capacity) filters in boxes of a dozen for no more than 2 each (probably less). If you're willing to stump up for postage on top of his asking price I'll grab a boxful and mail them to you.

Steam n'Spares is on May 17th if anyone is interested.

Ian
 
11/04/2003 10:33:33   Alec   I too buy my oil filters at the spares weekends for between 1.50 and 2.00 each  
12/04/2003 14:21:43   allan   Thanks for all the help guys, sounds like my bank holiday is going to be busy.Still haven't found a manual if anyone could e-mail me the relevant pages i would be very greatful.Chears.  
14/04/2003 14:14:34   Steve H   My god, what a marathon discussion!
Welcome to the world of V4s. It sounds though like your initiation happened sooner than for most. I too have done this job parked on a North London street. If you havent got one, hire a hydralic engine crain fromm HSS or the like (about 30) and it makes the job if not easy, then just a job rather than a struggle. If it is the bearings that have gone, you will need to take the shaft out, and it comes out of the back of the engine. The work however can all be done on the crain though and should only take an afternoon and needs no special tools.

And a contraversial note about fibre cogs (where's that anorak). If the bearing is warn, a metal cog will only make things worse and maybe kill the rest of the engine when it fails. Part of any design process involves designing the part of the system that fails first. This is the balance shaft cog. If a metal one was used and it striped the teeth from the camshaft cog upseting the valve timing causing the pistons to hit valves, the engine would be very dead. I would stick with fibre and replace it in 25 years or so!

steve h

Good luck  
16/04/2003 20:22:19   louis   Hah! More fibres! Why then were Ford Transit V4's (German of course) factory fitted with alloy cam & balance cogs and steel crank cog? Maybe because they thaught they might take harder use than Saabs? Who knows...
I love this...  
24/04/2003 23:01:38   David   Allan,
Have you found a manual yet? Try www.ebay.co.uk - there are usually one or two haynes and/or Autobooks manuals on offer there. I have both and can email you scanned copies of the relevant pages (or copy and post to you) if required. The Autobooks manual (ISBN 0 85147 540X) is excellent and gives a lot of technical data in its Appendix - like shaft journal diameters, end float and backlash wear tolerances.  
03/05/2003 19:29:10   jake   louis i think the ford transit engine was an essex unit not colougne but i don't know about the timing gears  
06/05/2003 21:42:44   louis   Jake, you are right as far as the Uk is concerned but on the continent the cologn v4 was standard...  


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