Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > Porsche 924/944/968 Technical Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Coeur d'Alene, Idaho
 
Join Date: Aug 2017
Posts: 422
Garage
Don't toss those timing belt idlers and tensioners

So like anyone I'm trying to save money while I through 1000's at this project and one way was to not order new timing belt idlers and tensioners. I opted to listen to mine with a stethescope to see if they were still usable. And they were, though making just a bit of noise in a couple cases.

So I did an experiment I will report back on. I put some Mobil 1 synthetic gear oil into a syringe, and used a straight pin to pull the rubber dust seal back on each one. Injected fresh synthetic gear oil directly into the bearings. Wiped them off, spun them by hand and set them aside for install time. All were totally quiet except the balance shaft idler which had a click in it when turned slow that sounded like a ball bearing assembly missing a ball.

All of them weeped a bit of the fresh oil back out of the seals, so I know I effectively lubed them well. Very quiet and very smooth. I gave them a nice wipe down to remove the weeping and will have to see if I overlubed them.

These had only 59k miles on them and it sounded like the grease inside had simply dried, so the gear oil will likely cause that to dissolve into a nice slippery lubricant for another 10 years. Will see and report what happens.

Dof
__________________
84 944, 87 Vanagon, 88 Mitsubishi Van Wagon, 88 Supra Targa, 1990 Audi 90 20V Quattro sedan, 1992 Lexus LS400, 1993 LandCruiser, 1997 LandCruiser, 2017 Subaru Outback.
Old 09-18-2017, 11:27 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
9FF 9FF is offline
Registered User
 
9FF's Avatar
 
Join Date: Sep 2011
Location: Florida
Posts: 1,526
Tell me you are just kidding, right?
__________________
Mike A
9TECHNIK | TRANSAXLE ÄRA
1986 944 (Street); 1986 944 (Track); 1986 951; 1989 951 (3.0L 8V); 2000 996 Cab.
Old 09-19-2017, 04:02 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered User
 
Alexb944's Avatar
 
Join Date: Jun 2016
Location: Knoxville, Tn (USA)
Posts: 208
Garage
yeah, not very smart to re-use those no matter how quiet they spin.
__________________
The cars we drive say a lot about us.

1987 Porsche 924S - RIP
1985.5 Porsche 944 Lux - Daily Project
2002 Mercedes-Benz C320 Sportswagon - Daily Problem
Old 09-19-2017, 05:02 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Registered User
 
Join Date: Jul 2004
Location: Upstate New York
Posts: 2,204
And, here, I thought I was the cheapest guy around!!! LOL

I have a tip for you... don't reuse old brake pads...
__________________
Good luck, George Beuselinck
www.944ecology.com
Porsche Deconstructor (tm)
We buy 944s and sell 944 parts (845-379-1944)
We rebuild torque tubes and instrument clusters for 944/968/928
Old 09-19-2017, 05:16 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
plays with toy cars
 
sausagehacker's Avatar
 
Join Date: Jun 2012
Location: Houston, TX
Posts: 503
Garage
How long do you expect fluid to stay inside them at a few thousand RPM? They are replaced because the bearings have a lifespan. It's true that some bearing components are fine, but the rolling elements and races are subject to wear, even if you can't visually see it. It's not always explicit damage, such as pitting or fracture. They just go out of tolerance.
__________________
1983 944 - modded everything
http://forums.pelicanparts.com/dto_garage.php?do=viewvehicle&vehicle_id=28317

'86 951 - under construction
http://forums.pelicanparts.com/dto_garage.php?do=viewvehicle&vehicle_id=28374
Old 09-19-2017, 05:18 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Proprietoristicly Refined
 
John_AZ's Avatar
 
Join Date: Jul 2001
Location: ~Carefree Highway~
Posts: 5,822
I might try this on my 20 YO water pump bearing.....
__________________
1988 924S 77K July 2017 ...+ 1987 924S 145K DD (+15K est. bad odometer)
Old 09-19-2017, 05:24 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
9FF 9FF is offline
Registered User
 
9FF's Avatar
 
Join Date: Sep 2011
Location: Florida
Posts: 1,526
Quote:
Originally Posted by sausagehacker View Post
How long do you expect fluid to stay inside them....
...and where do think the oil will go when it comes out, all over your new belts that's where.
__________________
Mike A
9TECHNIK | TRANSAXLE ÄRA
1986 944 (Street); 1986 944 (Track); 1986 951; 1989 951 (3.0L 8V); 2000 996 Cab.
Old 09-19-2017, 06:04 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Coeur d'Alene, Idaho
 
Join Date: Aug 2017
Posts: 422
Garage
Well, I can't disagree with anyone's contention that the "best" thing to do is install new bits. No way to know until some miles accumulate. For scale, I probably got less than two drops in each assembly and I overstated that they "weeped" any back out. I left them all oily and put each in a sandwich bag on the theory that with oil on the outside of the seal lips it would work to dissolve any crusted remains at this crucial spot I might have missed from my careful cleaning. Then wiped them dry before install. I'd forgotten that until discussion started. I also ran the pin around the seal lips at an angle to scoop, and got some thickened tan substance I believe to have been original dried grease at the lips. So I would not expect them to be flinging a lot of oil in operation though some will happen and does also with a new unit. The belts are made of an oil/grease resistant material and would not be deteriorated by small amounts, nor would they slip as they are cogs. It would be expected that they would operate reliably in the presence of some oil mist, etc, since this is an internal combustion engine. In fact, my timing cover had a half teaspoon of oil in the bottom. Just making the point they are designed to operate reliably on an engine with some expected oil contamination.

The seals were all as new in terms of being pliable, indicating the bearings had not gotten hot, so I'd expect them to continue to function well to keep lube in and dust out. The grease they came with had likely dried as grease will do over 37 years and the car sat for about the last 10 years. Grease as you know is just oil with a thickening agent. When you open a can of grease that has oil you can pour off, it simply was made at max saturation and now some separates out from sitting. Same happens in an assembly when grease sits for long periods unchurned.

So, we will see how she goes. These are lightly loaded bearing assemblies and I felt their useful life was going to end due to dried out grease if kept in operation. This restored the lube qualities and I guess we'll all know how the experiment goes, eh? I have some experience with powertrain components and lube, having been GM's world wide powertrain planner, and also a product planner for Lexus as well. Sometimes these subjects are much simpler than they appear. And sometimes the mad scientist blows up the lab. Let's see what happens, eh? Off into the uncertain future and all that sort of rot!! Heh....

Doug
__________________
84 944, 87 Vanagon, 88 Mitsubishi Van Wagon, 88 Supra Targa, 1990 Audi 90 20V Quattro sedan, 1992 Lexus LS400, 1993 LandCruiser, 1997 LandCruiser, 2017 Subaru Outback.
Old 09-19-2017, 07:19 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Registered User
 
Join Date: Oct 2002
Location: Boulder, CO
Posts: 747
If the seals can be displaced you can usually inject fresh grease and I have also heard of using vacuum to draw in grease.

I have had great luck in re-greasing alternator and serpentine belt idler bearings, have not tried it with timing components though.
__________________
1987 928S4
1992 968 cabrio
1994 968 cabrio - Supercharged
Old 09-19-2017, 07:56 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
Registered User
 
Join Date: Nov 2004
Location: Alberta, Canada
Posts: 2,698
A swipe of sealant over the hole where the needle went in and you're GTG. Anyone who keeps an eye on the condition of his belts is fine doing this. It would be a different story if one did this, installed the rollers and ignored them completely. I've often looked at these rollers and wondered about sourcing new seals for them and rebuilding them. If your 944 is a hobby car then why not experiment? I say more power to you, as long as you're fully aware and comfortable with the potential consequences.
__________________
'84 944 - new-to-me DD!
'83 944 - looks like ass, runs like horse - in primer.
'82 931 - roadster project - forever incomplete.
'80 924 - spouse's yellowjacket.
Some wrecks and a 924 racer.
Old 09-19-2017, 08:26 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #10 (permalink)
Registered User
 
Join Date: Mar 2008
Location: Rancho Cucamonga, CA
Posts: 3,504
Do not reuse these.
I have NEVER encountered a set of idlers/rollers after a normal timing belt interval that were worth reusing. All loose and getting noisy.

they are WAY too cheap to bother with this...
Old 09-19-2017, 09:49 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #11 (permalink)
Registered User
 
Join Date: Nov 2004
Location: Alberta, Canada
Posts: 2,698
Ah - but you know the difference between a good bearing and a bad one. And if the good one just needs proper lubrication, then...
__________________
'84 944 - new-to-me DD!
'83 944 - looks like ass, runs like horse - in primer.
'82 931 - roadster project - forever incomplete.
'80 924 - spouse's yellowjacket.
Some wrecks and a 924 racer.
Old 09-19-2017, 10:26 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #12 (permalink)
9FF 9FF is offline
Registered User
 
9FF's Avatar
 
Join Date: Sep 2011
Location: Florida
Posts: 1,526
A quick google search and dig down to find a reputable site and you will see that the oil you added does absolutely nothing productive to either the grease or bearing and could in fact accelerate the wear. Adding oil to bearing grease.
__________________
Mike A
9TECHNIK | TRANSAXLE ÄRA
1986 944 (Street); 1986 944 (Track); 1986 951; 1989 951 (3.0L 8V); 2000 996 Cab.

Last edited by 9FF; 09-19-2017 at 02:43 PM..
Old 09-19-2017, 02:40 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #13 (permalink)
Coeur d'Alene, Idaho
 
Join Date: Aug 2017
Posts: 422
Garage
Good article. Thanks. We'll see what happens and as pointed out its a hobby car that will likely see less than 3000 miles a year. Plus I have a well tuned ear for issues and if the bearings go into distress mode, I'll square them away.

Also, I didn't puncture the rubber seals. I used an ordinary needle to tease the edge back, then dripped gear oil into the bearing from each side. I used a syringe with a plastic tip used to irrigate eyes or the like to drop a couple drops on the gap, then gently spun the bearing as some/most of the drop got sucked into the tiny gap, and lubed the rest of the lip of the rubber seal as it rotated the oily spot around. Once I did all 3 or 4 of them, I went back to the first, and "scooped" upward on the lip all the way around resulting in pulling out a bit of hardened grease that seemed loosened by the presence of fresh oil. Felt good to clean the lips and may have restored a better seal. Then left them all oily in sandwich bags until I wiped them off and cleaned the cogs with brake cleaner - taking care not to spray the seals.

Definitely unscientific, but I'll be curious how it holds up.

Also, the article implies the oil will not mix into grease and I'm not I buying that. I regularly use both Amsoil and Mobil 1 grease in tubs and when it sits on the shelf it separates. Stirring it quite easily recombines the thinner oil into the thicker stabilizers. I agree with the article that using heat and the like is how it is done in a production facility but my experience is that it also happens readily with a popsicle stick in a partly used tub of grease. So I'd expect the oil drops I put in to combine with whatever partly stiffened grease is in there and with the heat and pressure of use to churn into a thickened version of oil called grease.

Sure someone could make the case that the specific oil I used may not combine with the specific grease in these idlers but a lot of wahoo is made about incompatible oils and the like that is just that. These days of SAE standards for lubricant compatibility mean that I don't think you can find two oils on a shelf anymore that cause any issues whatsoever. Same with greases. That's a holdover from when our Dads were kids and there were no standards for oil, no governing bodies, no engineering oversight etc. Churn an oil together with a grease designed for bearings and you've got a thickened version of whatever oil you put in there. Perfect? Not by a long shot.

Sorry this is getting lengthy but I have two LandCruisers that have full floater rear axles with bearings packed with grease for the wheels, and a center diff full of gear oil in the center. When you don't service the bearings a seal lets gear oil come into the axle ends and contaminate the bearings. Over time it will completely rinse the bearings. I've helped other guys service their rear axle for the first time at 280,000 miles and the wheel bearings look like new and are reused. One in my town now has 380k on it and the bearings are still in service.

That was a lot of content for an experiment but there you have it. Heh...
__________________
84 944, 87 Vanagon, 88 Mitsubishi Van Wagon, 88 Supra Targa, 1990 Audi 90 20V Quattro sedan, 1992 Lexus LS400, 1993 LandCruiser, 1997 LandCruiser, 2017 Subaru Outback.
Old 09-19-2017, 05:46 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #14 (permalink)
Registered User
 
Join Date: Oct 2006
Location: va
Posts: 2,120
Garage
Not that I buy in to this if the seal is worn and possibly faulty if the metal has worn too much but here is a tool to do this properly...https://www.napaonline.com/en/p/BK_7151564
Old 09-20-2017, 02:44 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #15 (permalink)
Registered User
 
Join Date: Oct 2002
Location: Boulder, CO
Posts: 747
I have used a grease needle to great effect on my Audis, keeping the front suspension balljoints, etc. alive and saving hundreds of dollars. If there is room to get grease into timing belt idlers it might work there too, from what I have observed the grease migrates out and then the bearings run dry. If one could keep them lubricated they might outlast the chassis.
__________________
1987 928S4
1992 968 cabrio
1994 968 cabrio - Supercharged
Old 09-20-2017, 03:13 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #16 (permalink)
Coeur d'Alene, Idaho
 
Join Date: Aug 2017
Posts: 422
Garage
Yeah, that is a good idea and I have one of those. With 8 CV boots on my Audi, I have also used it to sneak under the edge of the boot and fire fresh grease in now and again. Also had a Vanagon Syncro with 8. Wish I had thought of it as well here. Will be interesting to see how long this lasts though not a pure experiment as they only have 59k on them. So, likely a lot of life left in their tolerances.
__________________
84 944, 87 Vanagon, 88 Mitsubishi Van Wagon, 88 Supra Targa, 1990 Audi 90 20V Quattro sedan, 1992 Lexus LS400, 1993 LandCruiser, 1997 LandCruiser, 2017 Subaru Outback.
Old 09-20-2017, 04:06 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #17 (permalink)
Registered User
 
SReppel's Avatar
 
Join Date: Jul 2012
Location: Abbeville Louisiana
Posts: 123
Garage
In my experience I have found that it is hard to find good replacement bearings for most equipment. Discussions I have had with Auto Parts store guys agree, as most are made in China now.

Once after repeated failures of the shaft bearings for a grass mower I decided to remove the plastic seal on replacement bearings to see how much grease were in them. There was only a slight dab in it, surely not enough to insure that the bearing would last awhile.
I packed the bearings with a good grease and they never failed again.
I've done this on many other bearings even for my BMW motorcycle.

So I've also done this on my 944 belt rollers and tensioner. I cleaned out the dry grease and repacked them. No problems with any of them since I've done this. I did check them for slack though before doing so.

I guess it's a roll of the dice either way.
Old 09-21-2017, 05:22 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #18 (permalink)
Registered User
 
Join Date: Oct 2002
Location: Boulder, CO
Posts: 747
Hah, yes I have done a similar thing to new alternator and belt idler bearings. It's important not to overgrease these, you do not want the rollers plowing grease all the time.

In my 928 alternator, putting in new Chinese premium bearings, I found the amount of grease from the factory to be quite paltry so I added a few small blobs of good synthetic grease for good measure. Same story in new belt roller/idlers. Lube sure appears to be the issue with these bearings, the grease migrates out and the bearing runs dry and wears out.

There is a lot of value to me in a part that is installed and working and might just need a dab of grease vs a new part: possibly counterfeit, possibly flawed, untested. In some cases I'll still go the new part. It depends.
__________________
1987 928S4
1992 968 cabrio
1994 968 cabrio - Supercharged
Old 09-21-2017, 06:19 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #19 (permalink)
Banned from Boulder
 
Join Date: Apr 2010
Location: Arizona
Posts: 2,934
Garage
Finding quality new bearings is not at all hard. Amazon carries a ton of SKF, FAG, Nachi and Koyo bearings, most of the common sizes have same day delivery in my area. I've probably replaced 50 ball bearings since the last time I installed a chineese bearing.

Napa also has SKF bearings in stock.

My biggest gripe about the chineese bearings is they frequently don't clean out all the grinding dust. It's obvious as soon as you take it out of the package.
Old 09-21-2017, 09:26 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #20 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 05:30 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.