roshi

Hello All!

About 2 and a half years ago I purchased my 1998 LS400 from a local car lot with 129,337 miles on it.
Before buying it I went to a shop that a family member recommended to me and I got a pre purchase inspection done and this is what came back:

- Valve Cover Gasket
- Control Arms Upper & Lower
- Rack and Pinion
- Rear Pads and Rotors
- Timing Belt with Waterpump
- Spark Plugs

I knew that LS400s were notoriously known for being super super reliable and beefy cars so I figured that once all of this was taken care of I would be good so I went ahead and purchased the car for 3k.
Below I have listed the Repairs done to my car along with the Date the services were performed.

5/28/20:
- Brake Fluid Drain/Fill
- Coolant Drain/Fill
- Power Steering Drain/Fill
- Rack and Pinion
- Rear Pads and Rotors
- Control Arms Upper & Lower
- Valve Cover Gasket
- Skid Plate Replacement (did not have one when I got it)

6/29/20:
- Drive Belts
- Serpentine Belts

2/8/21:
- Front Pads and Rotors
- Power Steering Drain and Fill

4/20/21:
- Timing Belt and Tensioner
- Water Pump and Pulley

At this point my transmission had started to show signs of wear. I went to pick up some family members one day and I parked my car and left it running in their driveway and when I came back out I noticed a very had lurch from the transmission when going from park to reverse.
This only happened that one time but as soon as it happened I took it back to the shop for them to check it out and advise.

7/26/21:
- Coolant Drain and Fill
- 2QT Trans Fluid Drain/Fill
- Radiator Condenser Fan
- Tech Advised "Transmission Fluid very dark. Would not advice complete drain and fill to prevent damage to seals"

8/18/21:
- Alternator
- Radiator
- Upper Radiator Hoses
- Coolant Bypass Hoses
- Thermostat
- Gauge Cluster completely failed (no needles, no lights) so replaced with one off of a Junker
- 2QT Trans Fluid Drain/Fill

9/16/21:
- Starter
- ECU Failed so replaced with one off of a Junker (started throwing me codes for anything and everything. car also showed loss of power)
- Camshaft Position Sensor
- 2QT Trans Fluid Drain/Fill

11/19/21:
- Rear Struts
- 2QT Trans Fluid Drain/Fill

2/1/22:
- Ignition Switch
- Battery Cable Ends
- 2QT Trans Fluid Drain/Fill

Currently as it stands now my car still runs and drives great after getting over the initial hurdle of shifting into gear for the very first time in the day.
Usually it takes about 5 minutes for my car to go into Drive from Park so I try and get some fluid circulating in Reverse which it has no problem going into before shifting to Drive.
My question to you guys is this, do you think that going through having a new transmission put in and getting my rear main seal replaced is worth it after all of this trouble?
The shop that I have been taking it to for all of its repairs says that they think that the LS400 were great cars and that they work on them all the time but that they think my specific one may be a bit of a bad seed lol.
They have suggested to me that they feel like I would have better luck with a different LS or a different car all together as problems just continue to happen even with them looking into stuff ahead of time.

Thank you for taking the time to read and reply to this. I love my LS400 but I am beginning to feel like the problems will never end with this car. Please help restore my sanity lol.

Losiracer2

Yeah yours sounds odd, I've never seen an LS with that many transmission problems until about 250k or so. I have 162k on mine, 99', and everything works fine still, no ECU issues, I did do a radiator in 2020 and Timing belt/WP/Tstat/drivebelts/crank seal in 9/21. My cluster is sorta doing the sticky tach thing only when its hot outside, but tranny, I recently removed the pan and at 160k, the filter was nearly spotless, so I left that since its just a strainer, but did change the pressure dial to 1 from the 2 (middle position). I turned it one click left, for higher line pressure and quicker shifts, seems to like it so far after 5k miles. My tranny occasionally does a weird thing, when I'm on a pretty significant grade and let off the brake and want to barely creep up the hill, it gets confused and sometimes shakes before finding forward momentum. But never does this on level ground from a stop.

But previous owner did the alternator at 109k (assuming power steering idle valve made it fail) starter at 127k & strut rod bushings, Tbelt only at 90k at the dealer. My car was an Ohio car for most of its life though.

400fanboy

Well documented post - thanks for providing all this information. I'm sorry to hear of the list of troubles - I'm somewhat in a similar boat with my car (different problems, mostly suspension related). The trouble with this car is... it's true to say they are extremely reliable. Everything about them is extremely durable. But this being said... they do need a lot of looking after. I think if properly looked after, at 200,000+ miles they will be in a "lot better shape" and feel a lot better than comparable cars at a comparable mileage. But they aren't cheap to look after properly. So it's a double edged sword.

I have a question about the transmission. Does it shift harshly? My car bangs 2-3 sometimes at certain throttle & RPM positions. But otherwise it's nearly imperceptible. I ask this question because getting a lot of driveline slap & banging when shifting between park\drive\reverse can commonly be transmission mounts. The only thing that gives me pause for being firm on this diagnosis is the color of your transmission fluid. This indicates neglect for many many years, which also could cause these issues & more, presenting themselves as in it's inability to shift into drive until warm(er).

Also, while on this topic, what are the condition of your motor mounts? In park\neutral, rev the engine. If you get vibrations, the motor mounts are shot. The allowable tolerance here is zero. You should not be able to feel the engine revving up what-so-ever. However - this is a different topic and not really related to the issues you're talking about here.

I will agree with the above poster is that transmission failures are not a common thing with this car at all. But - if the fluid was black\dark, and someone didn't change the trans fluid for like 80,000 miles... then that goes out the window and who knows what's going on down there.

As for whether you want to continue throwing money at a problem car...? There is no good answer to this. On one hand, the issues could be endless and you just burn through money trying to keep afloat. On the other hand, you know the problems & the history and have already put all this money into it; and if you were to trade it for another LS400 you restart this process from day 0 with a potentially different set of issues and such.

The sunk cost fallacy. I don't have a good answer for you man. Best of luck finding a good solution.

Losiracer2

My problems were mainly suspension and exhaust related also. My Y-pipe was sputtering due to corrosion/salt in between the heatshields causing multiple leaks and flanges were badly corroded. Also all 6 of my rear eccentric and suspension arm bolts were seized in the bushing, fun times cutting them all out with a dozen sawzall blades. Did my front upper control arms recently 11/2021 and rear upper arms 5/2020 were beat due to potholed roads (loose balljoint and play in bushings). Still have to sort out the right rear lower knuckle bushings as there's slop to be found there also but hard to spend $284 a side for knuckles just to do bushings.

RA40

iTrader: (6)

I commend you and your wallet for doing this much maintenance to get it running well. Most of this would have been typical to bring the maintenance current. The ECU and cluster are oddities. There are no guarantees and sounds like the car had some levels of neglect. A hard shift may be related to the engine and transmission mounts. The tranny mount is not an expensive swap but the engine mounts are up there. Does the shift feel smooth between gear changes otherwise? The tranny pan may be dropped to inspect the shift solenoids since the fluid had been dark.

Are there signs of the RMS leaking? That's $$ to fix due to labor.

I realize you've spent some $ for all this so far. With the basics updated I would feel you are close. What is your intended term to drive this car? Once sorted it is very capable of many miles but if this is a short term one then determining how much wallet you can tolerate is a consideration. Has this car been in any rust belts states prior to your ownership?

400fanboy

I've been fortunate in some areas, not so much in others. The engine has been stellar in my car, frequent oil changes and driving it regularly and she doesn't leak or burn a drop of oil. Developing a bit of a hickup lately (in the thread you commented on) but still nothing major drivetrain wise, knock on wood.

Suspension is hard though. So many little things that can compromise the ride quality. I'm *STILL* chasing down a vibration. BTW you were right, every mechanic who looked at my car said my rear wheel bearing was on it's way out because of the 12-6 play in the wheel. I trusted your experience (and the fact that wheel bearings don't typically fail via play, they fail by making noise) and replaced the upper A-arm. And guess what, it's tight as a drum now.

That's now two suspension components that have "failed" where the actual part in question visually looked perfectly fine. No leaking, no grease coming out, no cracks in the rubber. Upper A-arm and front lower ball joints.

Gerf

My opinion is that you've been getting hosed by the looks of those repairs, some are repeats as well.

CLLEXUSS

I try not buy cars from local car lots, most of the time there turns out to be a lot of issues. For me my best experiences are purchasing from the owner who has owned it for a while. 3rd parties, car lots, auctions, all a toss up and you roll the dice. Price was cheap 3K for 129,000 miles, that seems pretty low for a car with those miles, my guess is someone knew something as it was sold because that's pretty cheap for those miles.

roshi

Thanks for the Reply!

Trans mounts and Engine mounts on my LS are solid as that was what the mechanic thought it would be also.
I forgot to mention but one of the trips up to the shop they alerted me that my car had thrown a P0700 code on the transmission which lead us to believe that the transmission was faulty.

One thing that I can absolutely confirm is that the car did not live the best life before I got my hands on it.
Previous owners did very little when it comes to repairs other than regular oil changes but it would be safe to say that the trans fluid was certainly neglected for who knows how long.

When it comes to the transmission shifting it does not ever shift harshly. In the mornings after I have not driven the car for 10+ hours or so when shifting from Park to Drive it does not like to immediately go into gear. Instead it takes about 5 minutes to get the fluid circulating (just guessing here) before wanting to engage to drive. Reverse works totally fine and instantly goes into gear same with everything else I only have a problem going into Drive.

Thank you again for your reply! I appreciate any help I can get haha.

roshi

Hello!
Thank you for taking the time to reply, after the initial shift in the morning from Park to Drive the car runs and drives great with shifts feeling smooth even from 1st gear onwards from a complete stop. I believe it is just the fluid being very dark and needing some time to move about the transmission (just guessing haha)

As for the Rear Main yes it is leaking at a pretty decent rate. When I park the car I notice a little puddle underneath where the trans meets up with the engine almost always.

I do intend to drive this car for as long as I can and don't plan on continuing to put so many miles on it once I get my truck in May. I would love to have this car as a weekend cruiser and dont want to do any aftermarket work to it at the moment, I prefer the stock look.
The car started life in Orlando Florida as a Rental Vehicle before being sold in 2000 to someone living in Houston TX and so on. The car shows no signs of any rust whatsoever. Only cosmetic issues is that there is a tiny tiny door ding from a previous owner (maybe the size of a dime).

Hope this helps a little bit! Thanks again for your interest!

400fanboy

Did the slow replacement (drain & fill) of the transmission fluid over the last year make your shifting issues get better, or get worse?

Is it worse on cold mornings vs. hot days?

roshi

To be real with you it does help for the first week following the new fluid being put in.
Instead of taking 5 minutes it will sometimes work instantly going from Park, to Reverse for a second then to Drive but after about the 2 week mark it goes back to taking about 5 mins to go into Drive.
Since its only 2 quarts at a time id say it works alright for the time being. I have only been getting the fluid replace with Toyota branded ATF.

I for sure notice a difference in transmission shifting performance for the first shift of the day when its cold. When it is warm it shifts a little better but still nothing great usually 5 or so mins to go into Drive.
Sometimes instead of it taking 5 or so minutes it will take upwards of 10 even after letting fluid circulate.

timmy0tool

iTrader: (7)

waiting 5 mins to get into D is too long! i know you said you use toyota branded ATF, but which one specifically? there are many, and you should only be using type-IV!

also check the fluid level, when hot (engine at operating temp), on a level surface! of course use the HOT side of the dipstick.

400fanboy

FWIW every LS400 hangs on the first shift of the day. It over-revs regardless of your throttle input and then SLAMS it home. It only does it once, only from a dead cold start.

It's considered normal behavior for the transmission at this point.

You've now circulated 8 quarts through the transmission - what does the fluid look like now? It's good you aren't experiencing slipping during normal driving - that gives hope for the transmission itself not needing a rebuild.

I'm at the end of my knowledge though. Best of luck for someone else sharing insight. It might require a trip to a dedicated transmission shop. The filter might be clogged (is there even a filter in our transmission?) which could be a easy fix... could be, I'm not sure.

paulo57509

In general, slow engagement usually means internal fluid leakage past hardened lip seals, etc. Because you have slow engagement in reverse only, and the transmission otherwise shifts with no slipping, the transmission isn't totally fubar, IMO. Seal replacement and other inspections and hard parts replacement = rebuild.

Is slow engagement only when shifting from P into D? Do you have slow engagement shifting from P into 4, 3, 2 and L as well?

Edit: In case anyone has the time and is curious about multiple drain and refills and how many of these are needed to "freshen up" fluids without fill bore fluid exchanges, go here for the "Partial Drain Helper":

https://bobistheoilguy.com/forums/th...2#post-5499500

My local Lexus dealership does fluid exchanges (not flushing with cleaning agents); time is money....