Transmission or drivetrain issues

[KCMOQ45T]

I've recently encountered some issues with my Q my baby recently blew a tire i put a doughnut on it and it was fine for a few days then it started slipping well the slip light started to come one so i would either pull over turn the car off and on and be fine or if it happened an i was on the highway or high traffic i put it in netural cut the car off and back on and it would either catch or all my lights would come on the abs slip light and trac control and it wouldn't slip again until the lights turned back off if i came to a complete stop but even that was intermittent.

I wad going to go replace that tire to stop the slipping because its not an issue i had when all four tires were right well it slipped and the car jerked and stopped moving i pulled over and tried to get it to do what it usually does ...well it just sat there i went through all my gears and it just sat on the hill i tried to put it in park and the car made a grinding noise like it was stuck in drive well i pressed the gas and the car went no where but it made a noise like gears where moving but no power i pulled the car to my uncles house around the corner from where i stopped it sat for a few hours i got in it and tried to shift and it went into gear an drove no prob i immediately parked the car an got the new tire the car drove. Great no issues the following day another back tire blew back on doughnut and slipping well same situation im traffic but the dash lights slip trac abs came on without me turing the car off i was coming to a light i was about to turn the car off but before i got a chance it jerked again an kinda popped and no power again same thing it sat a whole day pulled it home again after buying another tire and its just been doing the same thing. Ive checked the fluid in the transmission its not burnt or brown its not leaking any fluids just making a grinding noise when i put it in gear the car will also roll if i don't have it parked a certain way or e brake engaged ..someone offer some advice where to start what could be the issue i've been looking online and nothing matches my issues right now

[EdBwoy]

Welcome aboard, and sorry about the misfortune.
Here's a tip in case it happens in the future: If you have to use a doughnut, move the wheels around in whatever configuration you have to, but ensure the driving wheels have equal diameter tires.

Depending on the system complexity, all 4 corners are monitored for speed, and having a smaller tire will result in higher rotation in that corner (and vise versa). That's what causes your SLIP light to come on; which usually triggers the
1. TCS system to brake the respective wheel in conjunction with the ABS sytem
2. VDC system to cut engine power
to stabilize the vehicle. I'm simplifying, but those are the basics.
(slip = right axle spinning faster/slower than left axle).

On the 2nd issue of the grinding:
How large are the other wheels/tires and how long did you ride on the spare?
How many miles on the car?
The issue of similar sized driven tires is more compounded on vehicles with differentials (RWD) & transfer cases (AWD).
The way differentials work is that they allow a little wheel speed difference but not too much. If you do burnouts all day with an open diff, the spider gears will get messed up. Since the Y33s have viscous LSDs, I'm guessing something else happened in the differential as it was constantly trying to fight the slip

Here's where more diagnosis kicks in. You might need to raise & secure the car for some of these.
Since you said the trans can't hold the car in park, I think some gear teeth wore out. Which ones?
1. Differential
- is the grinding noise coming from the rear
- does the driveshaft still turn in gear with the rear wheels E-braked
- is the diff fluid burned with excessive metal flakes

2. Transmission
- is the grinding near the trans
- the driveshaft doesn't turn when in gear
- fluid, which you checked already. I assume by dipstick, but flakes will be most visible by draining

[KCMOQ45T]

There are no flakes in transmission fluid the grining is coming from the rear end i feel a vibration in the car when i put it in drive r or any of the gears it only stops in neutral

[KCMOQ45T]

I have 225 r 16s on the car i was on the doughnut for some time a few weeks got off a day popped another tire was on it a day then this happened

[KCMOQ45T]

It has 192,550 miles

[KCMOQ45T]

The gears in the differential could be worn damn sounds bad is it something i can personally fix ive done all the work to my Q and wanna keep it like that

[EdBwoy]

There are no flakes in transmission fluid the grining is coming from the rear end i feel a vibration in the car when i put it in drive r or any of the gears it only stops in neutral

Makes me think it's somewhere in the differential then, since the driveshaft shouldn't turn when in neutral.
For proper diagnosis, I would take it to a shop. However, for the cost of a used diff, I'd definitely consider replacing it instead.

But don't go through all that trouble on account of my assumptions yet. Let me reach out to a friend of mine who knows about differentials, to see if I'm making sense here.

[KCMOQ45T]

Ok thanks i really wanna get the car back up and running

[KCMOQ45T]

I also cannot put the car in park while its started it makes a grinding noise like if you tried to slam the car in park mid roll to stop it instead of putting your foot on the brake

[EdBwoy]

Is the car moving in these situations or just stationary while you change gears? If it's not moving, then I'm back to the transmission

[KCMOQ45T]

Is the car moving in these situations or just stationary while you change gears? If it's not moving, then I'm back to the transmission

The car is nor moving its sitting parked on a curb so it cant roll forward but when i change gears nothing happens no movement just grinding noise from the rear in when in drive the noise speeds up an gets louder in R its slows down im neutral it stops can't put it in park while the car is running have to turn it off then put in park

[Hawairish]

I'm not familiar with Q45s, but EdBwoy asked me to read into things...so here goes...

Not sure I'm following 100% of the symptoms, but I don't think the issue is the differential (or rather, that's not the primary failure in my mind, at this point). A busted tooth, depending on severity, would give an occasional hiccup while applying some load to the drivetrain. It'd be easily detectable at very low speeds (such as idle). Eventually, it could probably worsen, but not usually enough to cause any other drivetrain issues really.

Unfortunately, I don't know enough about the transmission to be terribly useful. I can tell you that either the ECU or TCU are capable of throwing codes, and that you can retrieve both sets of codes (the TCU codes can be pulled without a reader or tools). The instructions are available in your vehicle's FSM, along with a few other diagnostic procedures.

My guess would be to do diagnostics on your inhibitor switch, and confirm that it is providing continuity when it should. Also check for any loose linkages. This might explain the issues getting into Park.

Are there any dash lights that persist?

[KCMOQ45T]

The slip light trac and abs lights stay on when i start the car

[EdBwoy]

Thanks Hawairish, your input is highly valued.

KCMO, might you have video of these things? I am also trying to follow the sequence of symptoms.
Also, have you checked under the car for any obvious breaks or binding?

[ZiprHead]

I'm wondering if the posi-traction clutches have worn out in the diff.

[KCMOQ45T]

Is the car moving in these situations or just stationary while you change gears? If it's not moving, then I'm back to the transmission

[EdBwoy]

Any updates?

[EdBwoy]