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Thursday, July 2, 2009

5 Speed Shifter Rebuild continued.....

And now, back to our exciting conclusion of the 5 Speed Getrag Shifter rebuild process.......


Rubber parts on this Shifter must have been made with 1920’s technology. Most of the Shifter assemblies that I’ve seen have rubber parts that are melted and fully deteriorated. Ditto for the plastic bushings. I replace the plastic with Bearing Bronze, and use new rubber bushings that I buy from Delta – probably the same crappy rubber, but what the heck, it will last another 20 years and can easily be replaced (this is the only part that is easy to replace).
Then there are the small 0.235 diameter pins that fit in the linkage. Well, these are always bent (you can actually see the bend in the photo, lower right) and the holes have been forced into an hourglass shape. I replace these with case-hardened larger diameter pins. Of course, the mating holes have to be drilled out to the new diameter.
The sand contamination generally wears out the bearing holes in the aluminum casting, so the casting holes are opened to a larger diameter and new bronze bushings are inserted. See the photo of the new pins being inserted in the bushings in the “assembly” section below.

Time = 0 hr. (This photo was for the blog only.)


In order to obtain the best possible performance from the Shifter, I hold the machining tolerances to +/- 0.001 in. Sometimes I must use “persuasion” to get the parts to fit together.
If I specified “line bore” on my drawings, the shop would charge me twice what I now pay. I can make the necessary adjustments myself – my labor is free ! ! !
Really, it takes a few hours to get the assembly properly put together, with solid bearing function and elimination of all the slop that was in the original assembly.
Time = 2 hr. plus 1 beer.

Once the bearing sets are carefully seated, the final step is to lubricate and perform final assembly. That is the easy part. Easy is a relative term – in this case, it means no filing, sanding, burnishing etc. But, oiling and greasing is a messy business and I want to be certain that all the bearing surfaces have sufficient lubrication for the next 20 years of use. I apply three different types of Loctite to several places so the external bearing inserts don’t rotate and the set screw won’t back out.
Did you know that Loctite takes over an hour to dry???????? Have a beer while it’s hardening.
Time = 1 hr. plus 1 beer.

After assembly, the Shifter is a thing of beauty !
---Run to the Post Office to get a Priority packing box.
---Pack Kit in box.
---Enter address and tape box.
---Run back to the Post Office to ship. Wait in line.

Time = 1 hr. No beer. Well, after I get back from the Post Office, I had a couple………….

o These Kits turned out better than the mods I made to YELODOG Shifter – well, someone was paying me, so I felt compelled to do the best work possible.
o Fourteen hours of my effort per Kit – that’s a lot.
o 10 beers + 1 glass of red wine. I should charge for the beer…………….
o If I had orders for only one Shifter, I would be losing major $ because of machine shop costs. Having 3 sets of parts made at one time means that the shop had only one “set-up” per part.
o Set-up usually takes much longer than the actual machining of these simple parts. (while I attended university, I worked in a small shop and during my engineering career, I sent parts to machine shops on a regular basis)
o Set-up for one of the bronze bearings might take about 1 hr – machining each takes about 10 minutes. Thus:
§ Two parts at 40 minutes per part
§ Six parts at 20 minutes per part
o I’m happy to go through this effort for the benefit of other JH owners – a sloppy Shifter is a bummer !
o No, I don’t do installations.
o Memo to self: Do not take an order for only one Shifter Kit ! ! !

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