Tstelko

I have a NOS Shimano DEORE DX right shifter. My 1990 MTB has old lever locked in gear now. Any tips on how to swap these parts out? Is this a simple exchange or should I take it to a bike shop? Thanks in advance.

Iride01 

Simple depends on how well you understand everything else involved. You probably should change out the cable too. You for certain will need to know what all the pieces parts of the rear DR do so you'll correctly know what adjustment screw to turn. Limit screws are seldom the correct screw to turn for shifter and cable changes.

LBS's around here seem to be willing to give a good estimate of such costs for free. Nor do they charge much to do the stuff you need done.

jimc101

If you're just replacing the shifter, cut the cable (the new one should have one fitted?, if not, replacing a 30+ year old cable is probably a good idea) then install the replacement shifter

Crankycrank

Here's Shimano's Manual. Not sure but this may cover your model shifter. SI-T-2A-000-00-ENG.pdf (shimano.com) Also try to find the specific model number of your shifter and check YouTube videos for a more descriptive installation.

Andrew R Stewart 

There should be a model number molded/stamped into the lever, sometimes tiny print. Of course if you're going to a LBS just take the old lever with you. By 1990, IIRC, Shimano had gone to the second style of STI MtB shifters. These can see their factory lube get gummy with age and can be made to work again with simple cleaning and lubing (this issue is a common thread here). Not sure if this is your problem from the description but I usually like to try to keep the old stuff running as a first choice. Andy

Bill Kapaun

IF you have too much tension on the cable, it may be unable to release.
Just disconnect the cable (don't cut) and see if the shifter will then move.

Is it JAMMED against the largest cog?

ClydeClydeson

I would start by disconnecting the cable from the derailleur and see what, if any, function the shifter has. You can simulate a bit of spring tension from the derailleur by pulling gently on the cable. THe problem might be as simple, as mentioned above, that the shifter is jammed into a gear and the cable tension is preventing it from releasing.

If the shifter is indeed not functioning, and the shifters are of the same style, yes you can likely just unscrew the original and bolt in the new one. IIRC in 1990 almost all shimano DX shifters came integrated with brake levers - one clamp with brake lever and shifter attached. It that's the case, you can remove the old one by removing the allen head bolt on top (5mm?) and bolting the new one in place. When you get the old one off just double check that the mounting pattern on top of the shifter is the same - it should be.

Tstelko

Yes, the brake lever is integrated with the shifter. I dropped the bike off at a trusted local bike shop yesterday. This is the bike shop I got my first bike from in 1974 ! It was a Schwinn dealer then but has been a Trek dealer for decades. Waiting on an estimate. Asked to re-cable the entire right side too. Looked at the Trek Domaine SL5 road bike. Wow. Seems like a great bike for my needs. Going to ride the old MTB for a bit and see how it goes. I like the hunt for new stuff so will drag this old while I enjoy my old MTB.

70sSanO

I figure 2 weeks riding that old mtb and then you’ll be on the Domaine.

Congrats!

John

Tstelko

Just picked up my bike from the shop. They did an excellent job! Installed the shifter/brake combo, re-cabled the right side, replaced some rusted screws on the frame, and gave the bike some other attention. It is a much better bike now. Only cost $32 which made me very happy. Great customer service! Sadly, I don't see that often enough these days.