Speedometer gear

[paccool]

Well, the truck goes into the rear end shop this Wednesday. Finally going to get rid of the 4. 10 ring and pinion and get back to the 3. 54. The speedometer has been off about 10% since I got the truck but its off in the wrong direction. It reads slow instead of fast. Can anyone tell me which speedometer gear I will need to get it back to reading right? Part number or number of teeth would be good.
In lieu of that info, is this something as simple as going to a parts house and telling them what I want?

------------------
Stan
93 2WD extended cab, Banks Power Pack, K&N air filter, PW Injectors,rebuilt and tweaked pump, auto w/4. 10 rear with limited slip, US Gear Exhaust Brake, 3-1/2" Exhaust, 5K air bags, Boost/Pyro/Tach Gauges, Green/Silver, new 40-20-40 bucket seats, 151K

 

[Jones]

Hey Paccool, Is your truck 2 or 4 wheel drive? If it's 2 you're in pretty good shape. the piece that carrys the gear is offset and pretty easy to swap different gears on. Just figure out what gear you need stick it in the carrier on the tail shaft housing and rotate the carrier until the gear teeth engage. If its 4 you need to compute % of error so the speedo shop can fix you up with the right ratio adapter. I just went through it myself with my 4x4. Speedo shop had me plug my speedo cable into the transfer case direct (no adapter) and run past some mile markers to see how many tenths per mile I was high or low. In Cal, on the major freeways those motorist call boxes are supposted to be 1 mile apart and on some you'll still see the CHP airplane mile markers painted on the asphalt shoulder. Hope this gives you a start on your speedo fix.
Jones

------------------
Jones
'84 Ramcharger w/CTD, non-gated 12, torqflite, NP205, Dana 60 and 70 w/ 3. 07s. Looks more or less stock.

 

[fastmark]

JUst go to the dealer. They can fix up right up.

 

[B.G. Smith]

As stated above the gear is a dealer item. Before you go to the dealer, crawl under the truck and look at the piece the gear is mounted in, it has numbers on it and one of them will be lined up with an index mark which will be the one you have. You will need gear with fewer teeth with the 3. 54.

 

[paccool]

OK, finally got the speedo fixed tonight. Had the new gew gear for a few weeks but have been gone. The old gear was 38 teeth,the new is 31 teeth. Seems to be about right, have to run over to Reno tomorrow and will check on the way over. The gear cost $12, the O-ring about $2. Takes about 10 minutes to change. If anyone needs any help, E-mail me and I'll do what I can to make things easier for you.

------------------
Stan
93 2WD extended cab, Banks Power Pack, K&N air filter, PW Injectors,rebuilt and tweaked pump, auto w/3. 54 rear with limited slip, US Gear Exhaust Brake, 3-1/2" Exhaust, 5K air bags, Boost/Pyro/Tach Gauges, Green/Silver, new 40-20-40 bucket seats, 151K