Author Topic: manual shifter rods  (Read 4917 times)

jpmd1

  • Guest
manual shifter rods
« on: August 12, 2006, 07:35:36 »
Greetings,
I was trying to rebuild the shifter(bushings etc...) , and because of my "heavy handedness" broke the screw that sticks up from the right shifter rod . Upon further inspection, it looked like there is a 1.5 in end that can be unscrewed and replace. This is the end that has that broken screw.
Any ideas where I may be able to buy replacement.
Thanks

John P Gebrane, MD

rwmastel

  • Full Member
  • Platinum
  • ******
  • USA, OH, Canal Winchester
  • Posts: 4634
  • Pagoda SL Group: 20+ years and going strong!
Re: manual shifter rods
« Reply #1 on: August 13, 2006, 09:16:20 »
John,

I've not done any shifter bushings.  Does this post help?
http://index.php?topic=5567


Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420
Rodd

Did you search the forum before asking?
2017 C43 AMG
2006 Wrangler Rubicon
1966 230SL auto "Italian"

Naj ✝︎

  • Associate Member
  • Platinum
  • ******
  • United Kingdom, Surrey, New Malden
  • Posts: 3163
Re: manual shifter rods
« Reply #2 on: August 13, 2006, 10:28:49 »
jpmd1,

Have a look here:

http://www.sls-hh-catalogue.de/bin/dbframes.phtml?mid=IN02

Section 26 b for gear lever section.

You may need a new rod....
The ball joint is at the other end?

naj

68 280SL
68 280SL

Longtooth

  • Guest
Re: manual shifter rods
« Reply #3 on: August 16, 2006, 01:54:11 »
John,
Your description of what actually broke isn't clear (to me).  I just finished replacing all the bushings in my shifter linkages yesterday and put everything back together already, otherwise I'd have made some pics to describe the parts... and what their purpose is.  I took everything apart to make things work smoothly and be able to make the adjustments I wanted to be able to make.

It sounds like you're referring to something related to one of the 2 rods (1 rod on either side of the shift tube (splined at one end, attached to shifter lever under the sphere on the other end).

One end of each rod is rigidly attached to the bearing plate (the metal plate into which the split spherical bushings are inserted, and which holds the shift lever).  At the bearing plate end of these rods there's a 90 degree threaded end that sticks up thru the bearing plate hole thru a bushing, and a castle nut and washer that tightens this end of each rod to the bearing plate.... but which allows the rod to swivel (rotate) side to side... just not in any other direction.  Is this the part and end that broke? If so, you need to replace the rod itself.

The other end of each rod is a 25 mm long (~1 inch) threaded end.... at the end nearest the transmission. Is this the part and end that broke? If so, you need to replace the rod itself.

Onto this threaded end of each rod there's a piece that has internal threads (which screw onto the rod's threaded end) on one end, and a hole (with a bushing) on the other end (end closest to the transmission).  The purpose of this internally threaded piece with the hole & bushing in one end is to adjust the distance between the transmission gear changing rod's splined hole and the location of the shifter lever (bearing plate) by screwing this piece further onto the rod (shortening the distance) or unscrewing x revolutions (lengthening the rod). It's locked in place by a nut tightened up against the piece with the internal threads when the distance (length of rod) is adjusted to the specific length needed. This piece with the internal threads and hole and bushing in one end fits over a threaded shoulder rod that sticks up from (out of) the tranmission linkage unit (on either side of the actual transmission push rod that changes the gears inside the transmission).  It's held in place on the threaded shoulder rod (coming out of the transmission cover plate) by a castle nut and washer.

Is the part that broke the piece that sticks up out of the transmission cover plate & to which the internally threaded part that screws onto the rod attaches? If so you need to replace the right (as opposed to left) shoulder bolt that's sticking out of the transmission.

fwiw, I had a hellova time unscrewing one of the length adjustment pieces (pieces with the internal threads that screw onto the rod's threaded end (nearest the transmission end)... it was frozen... but after letting it swim in some liquid wrench  for a few hours and occassionally applying some torque... and pinging it (trying to let some vibration allow the liquid wrench to penetrate the threads) and then carefully applying pressure with pipe wrenches (one on rod, the other on the piece that screws onto it with the internal threads)  I finally got it moving.  I was careful though as the tendency would be to over-torque and break the rod in torsion....i.e. twist break.  I cleaned the threads (both internal ones and external ones, then greased them up (wheel bearing grease), and they're now as slick as a greased pig.... easy to adjust length of rod between tranny end and lever end by rotating the end piece by my fingers while it's down in the well.  

According to my BBB, the length of the rods is to be adjusted such that the screw ends on the bearing end of the rod (ends on either side of the shift lever) are precisely centered on the plastic housing that the 4 screws go thru to attach to the 4 body bolt holes (over the drive shaft)... WHEN the splined shift tube is inserted into the internal splined transmission rod piece by at least 15 mm.... AND that both rods are adjusted to the SAME LENGTH... i.e rod with rotating end pieces adjusted to same length overall (hole with bushing end that fits over the shoulder screw at transmission to bearing plate end bolts at the shift lever end).  If they're not the same length, then the shift tube will try to push at an angle (or shift lever will be twisted with respect to the shift tube) and cause premature wear the bushings between the shift tube and shift lever (4 such bushings... 1 ea. on either side of the shift lever hole, and 1 ea. on outside of fork on each side of the forked shift tube end).

In other words, the shift tube (splined piece attached to the shift rod) is a fixed length... but the location of the transmission rod (internally splined piece on the transmission) is some variable fixed distance from the center of the 4 bolt holes in the body's drive shaft cover).  To allow for that variable distance in one car to another, after the spline pieces are fitted together, and the center of the rod bolts at the shift lever end in the bearing are centered between the front and back bolt holes, then the splined pieces are fixed together by the tightening bolt on the side of the splineed piece (on transmission internal splined section).  That means that there's a variable distance on each car from the rod ends at the bearing (shift lever) end, to the threaded rods that stick up from the transmission cover.... hence the length of the rods has to be adjusted accordingly... by the internally threaded piece that threads onto the rods with the hole/bushing on the other end that fit's ovr the transmission shoulder bolts.

If this is confusing, you probably need to see a picture or blown apart diagram.

Longtooth
67 250SL US #113-043-10-002163
'02 SL500 Sport
« Last Edit: August 16, 2006, 02:05:02 by Longtooth »