Site News - 7/11: No New News Today | 5/10: Members: Log In to See Fewer Ads!
[General | Members | C900 | 9000 | NG900 & OG93 | 93 | 95 | NG95 | 99 | Sonett | Vintage Models | Clubs | Other Cars | FAQs | Gifts | Member Photo Galleries | Member Directory | Classifieds | Manuals | *Buddy Registry | *Mileage Registry | Polls | What's New | Raffle | Photo of the Month | Sponsors]

C900 Bulletin Board
1979-1993 & 94 Conv [Subscribe to Daily Digest]
(Search Author's Posts: e.g. Keyword:username)*Members Only

[Main C900 Bulletin Board | BBFAQ | Next by Date | Post Followup ] Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
FOR ANYONE WONDERING WHAT THE PINION BEARING DOES:
Like This Post: - Subscribe to Daily Digest for this Bulletin Board
Posted by AP [Email] (more from AP) on Sun, 14 Jul 2002 23:06:01 Share Post by Email
In Reply to: Should one worry about a worn pinion bearing, TL, Sun, 14 Jul 2002 13:47:57
Alert me when someone posts in this thread:
Members do not see ads below this line. - Help Keep This Site Online - Signup

The pinion bearing is a part most cars contain in the diferential. Saab manual transmissions and diferentials are contained in the same enclosed unit, they share the same housing and lubrication supply. In order to understand the pinion bearing you must know the path the engine torque takes to the wheels. starting as far back as we can go without getting overly complicated, the enging torque (twisting force) comes out of the engine at the flywheel. The flywheel passes power through the clutch mechanisim which goes to a chain drive which goes to the input shaft of the transmission. The input shaft passes power to an intermediate shaft located directly below it within the transmission. This intermediate shaft is entirely enclosed in the transmission. The intermediate shaft is the middle man so to speak, it takes power from the input shaft and passes it to the output shaft which is directly above it. the output shaft and input shaft appear as one long shaft, but they are split in the middle and require the intermediate shaft below them inorder for power to be sent from the input to the output, this arangement allows for the selection of multiple gears. The outputshaft sends its power to the large ring gear of the differential. Where the output shaft and ring gear meet there is a tremendous ammount of force pushing the output shaft up under acceleration of the car. to hold this output shaft from moving up is a molded brace of the transmission case. This does the job just fine but there would be too much friction against the surface of the hole in the brace and the output shaft, to significantly reduce friction a certain bearing is used between the outside of the output shaft and the inside of the brace. The bearing does exactly that, it BEARS the load of the output shaft and it does such in a way with little friction, using metal rollers. The problem is that the pinion bearing doesnt have a large enough surface area to accomadate the load placed on it by the output shaft. 100% of acceleration force is placed on this bearing. IN OTHER WORDS: how ever much power you put to the wheels doesnt get there without first taking its toll on the pinion bearing. because of this the pinion wears down quickly. when it wears it allows for movement of the output shaft within the "brace" this allows the gear on the end of the output shaft (AKA the pinion gear) to mesh impropperly with the large ring gear on the differental. The impropper mesh creates the whiring noise we call pinion whine. The louder the noise the more impropper the mesh and thus the more worn the pinnion bearing is. This lack of controll by the pinion bearing can also cause alot of driveline slop. This is noticed in transition from acceleration to deceleration. underacceleration the outputshaft is forced allthe way upward, when you let off the throttle and leave the clutch engaged you can feel a jerk as the output shaft is jerked from to top of its travel to the bottom of the travel. When you press the gas again its thrown back up again.

the only solution to this problem is one of prolongment, there is no way to correct it without replacement. To get the most life out of the bearing the transmission lube should be changed every 10,000miles at the most. I change the oil in my 900S's transmission every 5-7k miles. (its very cheap to do so.) another way to prolong the life of a pinion bearing is to reduce its workload....avoiding heavy acceleration WILL make the pinion last longer.

thankyou for reading, hopefully you clearly understand now. Any further questions can be directed to my email or this post.

Austin
1991 900S ~140,000mi 5spd 3dr

posted by 172.156.241...
Posts in this Thread:
Alert me when someone posts in this thread:
Members do not see ads below this line. - Help Keep This Site Online - Signup
Post a Followup

No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.

Name: Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
E-Mail: (Optional)
Re-Enter E-Mail: (Confidential & Secure - Not revealed to other users!)
Note: Please check your spam folder for BB responses.

Subject:

Posting rules are simple - No for sale/wanted ads may be posted here - use the site classifieds.
You may not cross-post your message to multiple BBs.
Not permitted: political/religious topics and being disrespectful (personal attacks, insults, etc...).
 Site Members do not see any red text, inline ad links, bottom of page anchor ads, box ads, or anti-spam check.

Message: (please no for sale/wanted classifieds - post those in the Saabnet.com Classifieds)
Links are now automatically made active, no need for any special code (or use the Option Link field below) - don't put links in () or end with a '.'
To add inline images to your post, use [img]http://www.domain.com/img.jpg[endimg] (or use the Optional Image Link field below).

Links are now automatically made active, no need for any special code (or use the Option Link field below) - don't put links in () or end with a '.'
To add inline images to your post above, use [img]http://www.domain.com/img.jpg[endimg] (or use the Optional Image Link field below).
Optional Link: (e.g. http://www.saabnet.com/)
Link Title: (Optional)
Optional Photo/Image Link: (e.g. http://www.saabnet.com/img.jpg)
Photo/Image to Upload: (Please be patient while file uploads)



StateOfNine.com
SaabClub.com
Jak Stoll Performance
M Car Covers
Ad Available

The content on this site may not be republished without permission. Copyright © 1988-2025 - The Saab Network - saabnet.com.
For usage guidelines, see the Mission & Privacy Notice.
[Contact | Site Map | Saabnet.com on Facebook | Saabnet.com on Twitter | Shop Amazon via TSN | Site Donations]

Random Saabnet.com Member Gallery Photos (Click Image)
This is a moderated bulletin board - Posting is a privilege, not a right. Unsolicited commercial postings are not allowed (no spam). Please, no For Sale or Wanted postings, SERIOUSLY. Classifieds are to be listed in The Saab Network Classifieds pages. This is a problem solving forum for over 250,000 Saab owners, so expect to see problems discussed here even though our cars are generally very reliable. This is not an anything goes type of forum. Saabnet.com has been a moderated forum since 1988. For usage guidelines, see the Saabnet.com Mission and Purpose Page. Please remember that you are not anonymous. Site Contact | Site Donations | Other Sites by SP - Poverty2Prosperity.org | Run Club Menlo Park | ScreenBot


Site Members do not see red text instructions, bottom of the page anchor ads, or box ads.
Click here to see all the Site Membership Benefits!