The speedometer works as do the trip odometers. The main odometer counts up very slowly like about 1 mile to 5 on the trip odometer. The trip one is correct. What is the usual problem with them? The caps or a failing motor or ?

 

Is the ratio always 1 to 5 and constant? Will you check the slow rate precisely?
This is important to distinguish the problem.

 

I am not sure if it is. It will be another week till I can drive it, need to check the brake parts etc. before driving it more.

 

I'll wait your feed back.
You have already investigated that the speedometer and the trip odometer worked properly and only the main odmeter was slow.

The way you ask is far better than those who only say, "Help. My car won't run".
It would be better to inform us the slow ratio is always constant or not. If the ratio is always the same and constant, it means that the logic circuit of the main odmeter is not OK. If not so, I need to analyze the circuit more.

 

Here is what I just did. The main od was at 0 tenths. I zeroed the trip od, and started the drive. What I noticed as the first count up on the main od to read 1 tenth was 7 tenths on the trip od. Since these are not long straight country roads here and traffic etc. it is not real easy to monitor the od. The next count up to read 2 tenths on the main od came at either 1.6 or 1.7 on the trip od. A neighborhood speed radar shows the speed o meter close to right on.

To me since the first count up was at .7 I was expecting the next count up to be 1.4 that was not the case.
Thanks for your help Yamae.

As a note of course I don't know where the main od was at my start point in the drive. When I get more time I'll try to be more precise with it, I need the right kind of road to do that. Not easy to find around here in daylight hours.

 

The 90-92 LS400 mechanical odometer has a high failure rate. Mine failed at about 125K miles. At least they are inexpensive to replace.

 

Yeah but what makes it mechanical? A motor? The trip odometer is electronic and works fine. Do you have a write up on how to replace it etc.?

 

On the 92, the trip is a digital readout and main OD is pseudo-mechanical. Half old school, half new. I believe a small motor drives its gears and perhaps the gears(or motor) are kaput. You might look for a junkyard cluster.

 

Judging from the ratio not constant, the problem is probably caused by the partially worn counter gear. Without seeing the actual unit, it's hard for me to tell whether the unit can be easily fixed or not.

 

Here is a photo I posted five years ago: https://www.clublexus.com/forums/ls4...ml#post5012939

At least some other Toyotas used the same odometer part number IIRC.

 

Unfortunately the assembly/part is no longer available for replacement.

The failure is either with the gears or the motor driving them. Do you have a very faint clicking noise coming from your instrument panel (normally a motor failure)? It's not very hard to disassemble the odometer assembly to replace the motor or clean and/or replace the gears with used one. You can normally find used assemblies on ebay/junkyard, but unfortunately they're going to be rather expensive for what you want given most people want to replace the needles etc not just the odometer. Lexls.com's tutorial for instrument cluster removal is very useful. The actual odometer repair once you have the part is not hard at all once you have found some good used replacement parts. Good luck!

 

There you go. The post by Kansas (#10) has most all of the info you need to take that puppy apart and see what is wrong. You might be able to repair it yourself.
Great pics, Jim!