BCM Community

Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: mung on August 25, 2014, 07:21:43 AM

Title: PD-4104 Shift Linkage
Post by: mung on August 25, 2014, 07:21:43 AM
Should there be any bushings or anything like that on the shift arms at the transmission where the pin goes in for the linkage?  I looked at the parts book and don't see them listed, but there is a LOT of slop in that linkage.  One would think that you wouldn't want all of that movement in that linkage and the bus did have some issues with getting stuck in 2nd.

Thanks,
Vern
Title: Re: PD-4104 Shift Linkage
Post by: eagle19952 on August 25, 2014, 12:12:04 PM
can you fit over sized pins ?
Title: Re: PD-4104 Shift Linkage
Post by: mung on August 25, 2014, 12:40:53 PM
I will have to check, but I would say yes; however, if there is supposed to be some kind of bushing there, then that probably helps with the slight rotation of the pins while dampening side to side and up and down movement. 
Title: Re: PD-4104 Shift Linkage
Post by: gus on August 25, 2014, 03:41:18 PM
I can't remember for sure about those arms, but all the other linkage arms have bushings and are very prone to wear.

I spent many hours replacing all mine plus the pins at the trans, but don't remember any bushings.

The parts book should show this, maybe in the common hardware section.
Title: Re: PD-4104 Shift Linkage
Post by: chessie4905 on August 25, 2014, 03:59:04 PM
   Is the slop at the trans arm or at the rod tower at bulkhead center at rear of engine. You should remove the tower assy and replace/repair/rebuild it. The little arms on the tower have bearings in them. The tower transfers movement of rods in coach tunnel to rods to trans. Mark position of the rods so you don't mix them up. I don't know what parts are still available for that tower, but fix it once and be done with it. It also has a grease fitting at bottom. Fix it first and then grease it regularly. We put all new in our 4104 several years ago and eliminated all slop in the linkage.
Title: Re: PD-4104 Shift Linkage
Post by: luvrbus on August 25, 2014, 04:00:42 PM
If no grease zerk it won't have bushing
Title: Re: PD-4104 Shift Linkage
Post by: mung on August 25, 2014, 04:22:06 PM
I am talking about these linkage connectors.  See how much slop there is in the back one?  That can't help shifting at all.
Title: Re: PD-4104 Shift Linkage
Post by: luvrbus on August 25, 2014, 04:45:17 PM
The yokes look ok just drill the levers out to a standard size self lubing composite bushing or a blunting bearing and yokes are easy to find if wore out
Title: Re: PD-4104 Shift Linkage
Post by: chessie4905 on August 25, 2014, 05:41:38 PM
   Is that just side to side slop or is the arm or yoke egg shaped? The side to side can be tightened up with appropriate sized washers.
Title: Re: PD-4104 Shift Linkage
Post by: mung on August 25, 2014, 05:47:55 PM
Don't look egg shaped, just look like at one time there was some kind of bushing in there that is no longer there.
Title: Re: PD-4104 Shift Linkage
Post by: gus on August 26, 2014, 06:05:45 PM
As I remember there are about six of those yokes and pins on each linkage, maybe more.

I replaced every one of those for clutch and shifter. Also the arms of the Al bellcrank on the firewall were severely worn, bushings were completely missing from some of them and they are very hard to find.

A little slop at each one of those results in a lot of slop at the trans/clutch end.
Title: Re: PD-4104 Shift Linkage
Post by: mung on August 26, 2014, 06:17:43 PM
I will have to see what I can find that will work in place of the bushings if I can't find the real ones.  There has to be something that will work.
Title: Re: PD-4104 Shift Linkage
Post by: luvrbus on August 26, 2014, 06:33:14 PM
All mill supply will have some type bushing any yoke is available from MSC Industrial Supply in NY so are the bell cranks I buy the composite self lubing with a flange on 1 end and drive it in with the flange side then use a 4 inch grinder to remove the flange if needed   

Composite bushing are easy to work with, easy to ream for a fit the self lubing is a plus then they last a long time just don't waste your time with nylon bushings from Ace Hardware BTDT  :P   
Title: Re: PD-4104 Shift Linkage
Post by: eagle19952 on August 26, 2014, 06:44:56 PM
http://www.graphalloy.com/html/type_317.html (http://www.graphalloy.com/html/type_317.html)
Title: Re: PD-4104 Shift Linkage
Post by: mung on August 27, 2014, 05:19:30 AM
Thanks, now I just need to find the right size.
Title: Re: PD-4104 Shift Linkage
Post by: chessie4905 on August 27, 2014, 07:01:14 AM
   Make sure that the pins weren't replaced with the next size smaller ones.
Title: Re: PD-4104 Shift Linkage
Post by: olebusman on August 27, 2014, 07:39:55 AM
I think the bushings I used were for slack adjusters if old age hasn't set in.   
Title: Re: PD-4104 Shift Linkage
Post by: mung on August 27, 2014, 07:47:22 AM
I don't know how I would know if they are replaced with smaller ones.  I guess I could get a micrometer and check them against spec.
Title: Re: PD-4104 Shift Linkage
Post by: eagle19952 on August 27, 2014, 08:55:02 AM
buy new yokes, measure the pin, buy a drill bit....I think Clifford posted that twice... ;D
Title: Re: PD-4104 Shift Linkage
Post by: mung on August 27, 2014, 09:52:36 AM
Looks like Granger stocks some yokes too. 
Title: Re: PD-4104 Shift Linkage
Post by: eagle19952 on August 27, 2014, 10:13:28 AM
napa does too... get new pins yokes bushing and maybe two drill bits, based on the OD of the bushing...and a drill press with a proper clamping vice.
Unless you are able to find a machine shop...
or use a hand drill, your call... ???
Title: Re: PD-4104 Shift Linkage
Post by: mung on August 27, 2014, 11:21:24 AM
I have a small drill press that you use a hand drill on, but if I am going to be doing a lot of this type work, I probably need a real one.  My shop is a mess right now, so that needs to get cleaned this weekend, in order to make working through this stuff a bit easier.
Title: Re: PD-4104 Shift Linkage
Post by: chessie4905 on August 27, 2014, 05:42:25 PM
   Have you actually taken any of the rods off and checked them for worn egg shaped holes? use drill bits to check for size if you have a set that goes to 1/2 unless the pins are 5/8 or larger; don't remember and manuals went with coach. You could go to Lowes or equiv for larger size bolts to check fit.
Title: Re: PD-4104 Shift Linkage
Post by: mung on August 27, 2014, 06:15:40 PM
Haven't gotten as far as pulling them yet.  Probably this weekend.
Title: Re: PD-4104 Shift Linkage
Post by: mung on September 24, 2014, 05:21:44 PM
"Make sure that the pins weren't replaced with the next size smaller ones"

Chessie, how did you know?  Pulled one today and it is WAY too small.  Why would someone do that?
Title: Re: PD-4104 Shift Linkage
Post by: chessie4905 on September 25, 2014, 12:48:48 PM
   Been a mechanic forever and around  coaches and busses many years ; you see about anything over that amount of time.
Title: Re: PD-4104 Shift Linkage
Post by: mung on September 25, 2014, 12:52:29 PM
Seeing as no one seems to stock the 3/4" ones and the original GMC part has been out of manufacture for a very long time, I am sure someone just slapped what they had in the shop in there.  Hopefully it will shift a little better without all of that slop.