scottishmaximus

Hi, i just found this site looking for information on replacing the timing belt on my 1984 944. There was an erratic tapping coming from the timing belt cover that i could feel and upon investigatoin it appears as if the belt tensions are loose. I have read posts that recommend replacing rollers, tensioners, balance shaft belts, even engine seals, and the water pump. Not sure if i wanna replace the water pump and engine seals though. but i do want to make it right.

My biggest worry on the whole project is getting the belt tension right, and this seems to be the biggest concern with most people. What do i do to set the tension without paying the big bucks for the tool? Can I get it by hand? Can I rent a tool somewhere? Anyone have one near Cincinnati Ohio?

Any recommendations for the whole job would be great.

Thanks in advance

Scott

Stuttgart951

First and foremost - stop driving the car. Im sure youd much rather pay $350 for belts and pullies than $3500 for engine work.

See <a href="http://www.paragon-products.com" target="_blank">www.paragon-products.com</a> for in depth tech articles on almost every job you can think of.

Retentioning is touchy and it must be done right. My advice is (since this is your first time) either spring for the tool or have a mechanic do it. Id like to help more, but there are other listers than can be of MUCH more help that I.

Good luck.

Der Cupmeister

Welcome !! I also have an '84 944 and have done just about everything but a transaxle rebuild on the car in the 4 years we have had it. Due to the expense involved with having a belt or roller fail (valve to head interference) it is very common for 944 owners to replace the waterpump, cam belt, balance shaft belt, and all rollers and tensioners associated with these belts every 45,000 miles. Some change the belts every 30k and pump at 45k. When the new belts are installed the tension must be rechecked at approx 1500-2000 miles and then every 10k after that. It is convenient to change the front seals when you do the waterpump as all the pulleys, rollers, covers, etc... are out of the way. You can easily spend over $500 doing all this at one time just on parts and that is getting a rebult pump. Now onto the tension issue.
Yes, there is a special tool used to set the belt tension if you prefer the factory method. There are also some alternative devices available that are used with success by some members of this forum. There is also a Rennlist tool club that you can join if you have a Rennlist membership that gets you very reasonably priced access to the "Tool" and several special wrenches that make the job easier. I think the deal is you pay the shipping charges for the package and also promise to return the tools in a timely manner. Then there is the shade tree method also used by some members.
If you are interested in that technique we can discuss it privately as I don't want to incite a riot !!
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

scottishmaximus

Thanks for the posts. I already quit driving the car and have taken the cover off. I plan on doing the work myself. if i can't get a tool i will probably take it to a shop so they can adjust the tension. hopefully i might be able to find one that i could borrow or rent.


to me this whole timing belt thing seems like a hassle and a major drawback on the car. i have replace timing belts before on other cars and never went back to adjust. I would think that Porsche could have incorporated some type of self adjuster. oh well...love the car

C5Driver951

Funny, in 1987 they did add a semi-automatic tensioner. I don't think they foresaw the amount of expansion these engines have when up to temperature.

You should be able to buy a kricket tool at Napa to adjust the tension. I have a similar tool I bought from Markus at Blaszak Precision.

Make sure you replace the stud for the tensioner when you replace the rollers. I know of a few failures of that particular part causing massive damage.

scottishmaximus

C5Driver951- is the kricket tool a safe alternative to the Porsche tool? just wondering if they can be calibrated the same. Is this how you adjust yours?
Thanks for the tip on the tensioner stud

Bones944

Just finished up my n/a today and had to settle for the hand method. Balance shaft belt was right the first time, but I had to tighten the cam belt just a tick more as it had some whirring. Quiet and smooth now. I had just done my 951's belts in June with the 9201 tool, so I had a good baseline memory of how tight each belt should feel. Make sure on the smooth tensioner for the balance shaft belt that you have about 1mm deflection on the belt at the top, and a .5mm gap at the bottom (use a feeler gauge). Also, before cranking the car for the first time, rotate the motor by hand and re-verify your timing marks. If you feel ANY resistance, (other than compression) stop and retime it.

scottishmaximus

thanks for the input. i just tore it all apart today and the balance shaft belt appears to be loose. i can slide it side to side with little resistance. the lower balance shaft belt roller needs to be replaced. i didn't think it was a bad job at all to tear down to the belts for those of you who haven't done it. not sure what else i'm gonna do besides replacing the roller. belts appear to be fine. the previous owner said he replaced the belts not long before i got it so i will adjust them, just gotta get a tool.

Bones944

Previous owner of my car said he had just done a belt job too....however the belts were the only things he replaced and the smooth tensioner locked up and sheared all the teeth from the BS belt. I would buy a kit ( $139 from Vertex, includes both belts and 2 tensioners and 2 rollers) and replace it all while I was in there. Check the waterpump pulley for any play and replace that too if any play is found.

Chris_924s

make sure its cool (not driven) for a full day prior to tensioning.. and mark locations for everything!!!
John D.. Toolmeister.. will have a set to rent- cheap!!