How to inspect auto trans. for damage? - Toyota Nation Forum : Toyota Car and Truck Forums

silkydraws · 07-06-2010, 01:54 PM

Besideds looking in the pan? I ask because I was given (free) a low mile auto trans for a 98 4 cyl Camry because the guy said he really suspected it was towed wrongly. He said it came in the yard backwards with the front wheels on ground and back end on a dolly (because of badly wrecked rear wheel) He was suspect that the person did not do the proper 1) start car in park, then put in R then in N, then kill engine and leave in Acc. to roll backwards and even thought it may be have been in R the whole time (75 miles or so). I have heard ots of problems from RVers saying to haul forward that car must go from D to N before towing but never heard about towed backwards. Anyway, is there a spot to check for debris, maybe the end cap,cover of the drums. I doubt anything would have made it's way to the pan because while he did start the car before pulling engine/tranny, he didn't go through the gears because he thought it was already shot and couldn't drive it anyway to check for shifting. Any thoughts before I haul it to a tranny shop to ask?

***zythr*** · 07-06-2010, 05:29 PM

Probably check the fluid, and see if it will go through the gears, then check the pan. Sad that the tow truck driver should have had either a flatbed tow truck or the the wheels with spacers that would keep the driving wheels off the ground.

silkydraws · 07-06-2010, 10:34 PM

can't go through the gears it's sitting on the garage floor. Just don't want to install unless I can see if there was any damage or not. People tow 4 down all the time,(as long as the above stated precautions are taken) but I'm wondering where damage would be if there is any. And where I should look for it. I mean it's possible they went from R to N and would have had it in the correct spot, but then again maybe not. guess they didn't care since it was going to the junkyard

Chris Crash · 07-06-2010, 10:43 PM

Towing with the drive wheels on the ground, no matter what gear, is idiotic. It puts wear on the transmission no matter what.

I was always told that when towing (behind like an RV or something) remove the drive shaft first.

Techniker · 07-06-2010, 11:10 PM

Why not have a look for yourself? The FSM for the transmission is available online. Since the transmission is sitting on the garage floor, I can't imagine a better time to check it. This is a golden opportunity to clean everything out too and make sure she shines. You could even look into a cheap rebuild kit. Make sure you retorque everything to spec.

-Techniker

Chris Crash · 07-07-2010, 09:54 AM

You can shift it between gears. Just grab hold of the shifter and move it.

73sport · 07-07-2010, 10:48 AM

If it was more than a couple miles don't waste your time as its likely junk!

Think of running your engine with no oil for 5+ miles. That's exactly what just happened to this trans!

As you suspect, because it wasn't started very little of the "fall-out" made its way to the pan for you to observe.

Chances are the final drive is OK, its in a pool of fluid. In short tho, you have multiple shafts spinning in bushings that had lube while the engine ran so these have some residual oil hanging on but it goes away over time. Then you have mutilple clutch packs with metal and friction discs which had no lube and spun dry for lord knows how many miles. You MIGHT be able to smell the burned clutches in the fluid but until they get fresh fluid into them, the old fluid and particals is mostly trapped.

PASS!

grandpapa · 07-07-2010, 11:56 AM

unless you have the need for it, otherwise, don't bother.
Most of the time, FREE = someone doesn't want it

silkydraws · 07-07-2010, 08:14 PM

Appeciate the replys and agree. I'm afraid any damage will be hidden unless torn down. The only thing throwing me is that when you look up 4 wheel down towing there are instructions that say as long as the tranny is lubed before a trip (and I'm taling about instructions for autos here) to make sure for every 7-8 hours of towing that the engine is restarted and gone through the gears, going from D to N before continuing. It's not worth taking out axles to tow behind an RV every time you tow, yet many do tow autos. I'm doubtful but still hoping. So the big thing would be the clutch pacs? See in the old days you could actually pullstart an auto by dragging it around 30 MPH in D but I don't think you can do that anymore. I guess the biggest concern will be if the guy actually even had it in N. I may look in it or haul it to a shop see if they know a way to inspect w/o complete disassembly. I know Toyo is pretty good about making tech inspections possible on their stuff, was hoping someone knew a shortcut to pulling apart. I've done old 3 spd autos (long ago and just a couple) but these new ones are something I really never wanted to have apart in my garage. I know knowlege is power and saved money) but it's also hard earned for a little payoff. In other words it may 20 years before I take apart another if I did this one.

SexieWASD · 07-08-2010, 06:27 AM

Well, if your not going to use it, your probably just going to toss it, or scrap it for metal, so get a big trash can and rip it apart. There really is no point in not seeing the insides.

73sport · 07-08-2010, 01:05 PM

Quote:

Originally Posted by silkydraws

Appeciate the replys and agree. I'm afraid any damage will be hidden unless torn down. The only thing throwing me is that when you look up 4 wheel down towing there are instructions that say as long as the tranny is lubed before a trip (and I'm taling about instructions for autos here) to make sure for every 7-8 hours of towing that the engine is restarted and gone through the gears, going from D to N before continuing. It's not worth taking out axles to tow behind an RV every time you tow, yet many do tow autos. I'm doubtful but still hoping. So the big thing would be the clutch pacs? See in the old days you could actually pullstart an auto by dragging it around 30 MPH in D but I don't think you can do that anymore. I guess the biggest concern will be if the guy actually even had it in N. I may look in it or haul it to a shop see if they know a way to inspect w/o complete disassembly. I know Toyo is pretty good about making tech inspections possible on their stuff, was hoping someone knew a shortcut to pulling apart. I've done old 3 spd autos (long ago and just a couple) but these new ones are something I really never wanted to have apart in my garage. I know knowlege is power and saved money) but it's also hard earned for a little payoff. In other words it may 20 years before I take apart another if I did this one.

SOME old auto's like Chevy's Power Glide used heavily in high HP Dirt Track cars today had two pumps in the trans. The front pump powered by the engines crankshaft (like today) and a rear pump (gone today). The rear pump was powered by the drive axels. If the axels are spun over 18 or so mph, the system could obtain line pressure enough to engauge the forward clutch packs and walla - like a stick shift the axle is now connected to the engine and can turn the engine over. Cost savings and other measures removed this unneeded option.

Although modern technology says there may be other ways to do this and some cars may support it today, but IDK never seen it.....
As for towing an automatic, when I worked at AAMCO the motor home guys brought in all kinds of burned up cars they drug through the states. Ultimately a trailer is the most relaible way to tow a front drive car. But futil attempts to use pumps and axle disconnects look good in practice, they always failed on 3000 mile trips.

silkydraws · 07-09-2010, 03:35 PM

Well you guys were spot on. Brought to trans. shop a bud of mine has. He said "well, maybe, lets see" then when draining fluid said "never mind". After pulling pan it was evident it was shot...bad. Thanks for the time to reply though guys I was just hopeful. He said it looked like someone pulled it while in gear cause their was so much debris.