tablante

hello all! i just recently just purchased a 93 sc300 automatic. Been wanting one for a while now and got a pretty good deal on it. It's in need of a little tlc and needs some suspension updates as 3 of the 4 shocks are blown and has a horrible clunk coming from the rear. overdrive button wouldn't push in and stay in to turn on o/d so i took apart the shifter only to find a piece of cardboard between the button and the contacts to keep it from disabling the overdrive. I'm sure I'll find more awesome things about it later on down the road.

my main concern at this point is that the odometer is not showing/ working. everything else aside from the traction control button seems to be working. any ideas on how this can be fixed? if a full gauge cluster is needed, what years and models would be compatible?

KahnBB6

iTrader: (5)

Hello and welcome to CL, tablante! Congratulations on the purchase! That may be a handful of things to address out the gate but none of it sounds too crazy.

As to your points...

--new shocks:

KYB GR-2 front and rear shocks are the easiest drop-in replacement but there are a range of alternative suspension options if you widen your search to include options for the 1993-1998 Supra MKIV Base and Turbo. Further, there are many drop-in coilover options available and also a couple of DIY coilover options.

--horrible rear clunk:

This sounds like it could be related to suspension bushings. On a hydraulic shop lift, get under the car and check all the rear bushings and look for any signs of deformation, cracking, separation or just plain looseness. Also it could possibly be related to worn out rear diff bushings. Only an inspection will show you. The OEM bushings (or full assemblies) can be replaced or you have some polyurethane options through companies like Figs Engineering, Battle Version or Energy Suspension.

--fubar'd O/D switch:

This sounds like it was deliberately forced into the operating mode due to some other issue with the overdrive circuit or the A340 transmission. The switch itself can be replaced with a spare part off ebay or from a WTB ad in our Marketplace section (this is a very common spare part that should be easy to come by). But I think it may be wise to diagnose the transmission and its overdrive circuits in case the issue is related to a transmission malfunction of some kind.

--nonfunctioning odometer:

The odometer gets its signals from two locations before either one or both signals are turned into your mileage reading. The first is the three-wire VSS sensor on the transmission. The second is one of the ABS speed sensors at the front of the car. First you would want to get the transmission's VSS sensor (and wiring) checked. Then get your front ABS sensors checked.

Do you have any CEL light on in the instrument cluster? Any ABS warning light constantly on?

For any instrument cluster repair work, if needed, we recommend Tanin Auto Electronix in Racine Wisconsin. They're intimately familiar with our dash clusters and offer repairs on any malfunctioning lighting or gauges as well as upgrades to LED type lighting for the needles and backlights. They also repair the climate control LCDs if they are blacked out and not functioning properly. They also test everything on an SC300 or 400 shop car before sending it back.

Additionally, any issues related to failing or leaking main ECU capacitors can be repaired through Tanin.

Tackle it one thing at a time. Almost every older project car needs a little TLC at first. Good luck!

tablante

great! thank you so much for the detailed response! it definitely gives me some good starting points. would a faulty vss still continue to let the speedometer function properly? i don't think I've driven the car long enough or cycled the ignition enough to trip a cel. The worn out struts as well as severly worn steering rack bushings make the car feel a bit unsafe to drive. the responsiveness of the car and steering wheel are poor.

KahnBB6

iTrader: (5)

No problem.

A faulty VSS would not give the speedometer the signal it needs to operate. Also, if the speedometer motor itself has begun to stick or fail to respond it would need to be repaired (send the cluster in to Tanin). The wiring between the two devices could be at fault but that's rarely ever an issue if the wiring has never been tampered with at the transmission.

Unless there were an immediately failure of any component you usually need 10-20 miles to trip a CEL. For instance when I diagnosed my EGR temp sensor and VSV a few years ago I had to drive 100 miles for the ECU to fully leave Closed Loop mode after I'd reset the main ECU by disconnecting and reconnecting the battery.

The worn struts for a car of this age is pretty common. I'd suggest considering what your plans are for the car and look into the many suspension options available.

I would also suggest ordering a set of SC/Soarer steering rack bushings from Figs Engineering (or Diazen Sport Tuning but they don't always stock them). Those rack bushings wearing out are a common issue that affects handling.

Also, if they have never been replaced before your lower front control arms (Front LCA's) should be replaced. I'd suggest a right and left matched set from a 1993-1996 Supra MKIV if you can still order them since they are cheaper than the Lexus SC equivalents from the same model years and because the rubber formulation is geared less for cushy comfort and more for good response and handling.

Upgrading the rear swaybar and fitting high performance summer tires will also improve the handling but consider a modified version of the "Lance" alignment for the Supra TT if you change the rear swaybar.

tablante

thank you for all the helpful information. i was able to get the odometer up and running, i had to replace that part, luckily i found a lkq near by that happened to have exactly what i needed. i also found out that the bulbs had been removed from the abs , traction control and trac light, as well as the brake light on the instrument panel. of course now those lights are illuminated. i was however able to get the brake light to go away. the e brake just needed some fiddling around with to get it to turn off. is there something that can be plugged in to be able to read live data of the abs sensors?

i did end up going with tein basis z, new bump stops, as well as new strut mounts, and new steering rack bushings. i found out that all 4 shocks were completely blown. I adjusted the basis according to the install manual provided by Tein, it lowers the vehicle a decent amount and looks quite nice. it definitely makes the car a bit more bouncy but a majority of the clunk is gone. I've got new sway bar bushings and end links as well. just needing to install them.