YODAONE

Observed about 1" of forward and back movement of the driver and passenger seat back (measured at top of headrest)

Thought this normal until compared with other LS400s which displayed no movement at all.

Since I acquired a spare passenger seat with no fore and aft movement, decided to disassemble it to survey the condition of left and right adjuster assemblies.

The 1996 units are much tighter, so decided to use those.

Theses are discontinued items, so purchasing new is not now an option.

The seat must be extracted from the vehicle to perform this service and a fair amount of disassembly of the seat is required.
Removal of numerous hog ring clips is required to gain access to necessary fasteners in order to separate the seat back from bottom frame...so new hog ring clips and hog ring pliers are necessary to reaffix seat covers to frames.

This is NOT a first time do-it-yourself project.

All moving parts exhibited expired lubricants.
Will clean and use correct lubricant at all joints and lubrication points.

Am seeking input on whether anyone has disassembled one of these brackets, otherwise applying fresh lubricant to internal mechanisms appears all but impossible.
The original lubricant is tired or expired so wear will become a factor.

Have considered immersing the adjusters in heated (thick) oil to ingress oil into the interior, but worry it will leach out.

The other issue is the large motor driven gear...
The shaft splines and gear broachment are sloppy.
First the gear is too thin so it warbles on the splined shaft, two there is slop in the spline interface area.

Finally, Toyota employed a durable cloth cover that is similar to the headliner and fabric covered door seals.

Am interested in locating a source for material.(but not seeking recommendation to visit a trim shop..)

Thanks.


Motor driven side

Reverse side.

Motor driven gear depicting spline area.

Splines at base are not best fit with gear.


Cloth covers that wrap around the mechanisms. The cover on the left is from the 96 and the right from the 99. The 96 is superior in that it employs stiched-on velcro strips, while the 99 relies on a splooge of glue.The 99 cutouts are better.



Hog ring pliers purchased from Mcmaster-carr. Coated hog ring clips # 90468-16019 from Lexus prevent rust stains.

Items referred to in this post are 72510D, 72530A and 71811C

Bylan

I'm interested in your findings and solution, my passenger seat in my 98 exhibits a bit of slop on the backrest portion as well. Annoys me when I reach around the back of it to look out the window while reversing.

YODAONE

The easiest solution is to locate a donor vehicle with seat adjusters that do not allow the seat to excessively flop forward and back.

Another approach is to drill the rivets and rebush and repair the internals.

You really need someone with necessary equipment to restake heavy rivets.

I acquired seats from a donor vehicle, extracted the adjusters and relubricated where feasible.

The nylon bushing on all the motor driven side adjusters were loose fitting which allowed the large driven gear to warble like a warped record.

Had H.R. Slater Company in Chicago fabricate proper fitting nylon bushings and they fit like a glove and hold the gear flat..no more floppy gear.
(Slater has template should anyone wish to acquire a set.)

This will reduce gear noise and excessive forward and back seatback movement.


New nylon bushing installed on passenger seat adjuster mechanism. Old bushing and 2nd replacement bushing for driver's seat.