| Author |
Message |
Steve Magnusson (91tr)
Intermediate Member
Username: 91tr
Post Number: 1211
Registered: 1-2001
| | Posted on Saturday, November 30, 2002 - 11:52 am: | |
Henry -- I hate to be alarmist, but I just confirmed on my '91 TR that the rear wheels will counter-rotate (with some moderate persuasion) when a gear is selected and engine off (rear wheels off ground of course). I can definitely feel the extra drag from the limited-slip clutches mentioned by JRV associated with the spider gear system, but it's not too Herculean. Here's the data:
gearbox in neutral (cold)
full droop
rear wheels rotate together
torque req'd on driven wheel = 5~10 ft-lbs
gearbox in 1st (cold)
full droop
rear wheels counter-rotate
torque req'd on driven wheel = ~80 ft-lbs
Good luck with the diagnosis/repair... |
Henryk (Henryk)
Member
Username: Henryk
Post Number: 356
Registered: 8-2001
| | Posted on Saturday, November 30, 2002 - 12:22 am: | |
Thanks JRV: I will reassess the situation tomorrow.....it is now very late!!!!!
I will then start a new thread, with "88TR" as the heading.
Thanks again |
JRV (Jrvall)
Junior Member
Username: Jrvall
Post Number: 217
Registered: 11-2002
| | Posted on Saturday, November 30, 2002 - 12:18 am: | |
I can't think of any way of telling if the diff housing is cracked from the outside other than irregular noises, the ones I've done were still driving fine, after the side cover cracked they started leaking oil and upon inspection of the oil leak, saw the side cover cracked...
in your case though, if you have been fiddleing with the parking brakes, I'd start looking there first. |
Henryk (Henryk)
Member
Username: Henryk
Post Number: 355
Registered: 8-2001
| | Posted on Saturday, November 30, 2002 - 12:11 am: | |
The differential was replaced when I bought the car....about 15,000 miles ago with a supposedly stronger 512TR unit. |
Henryk (Henryk)
Member
Username: Henryk
Post Number: 354
Registered: 8-2001
| | Posted on Saturday, November 30, 2002 - 12:09 am: | |
Can't really tell where the sound is coming from.
The parking brake shoes are off the car in the left rear.....am waiting for new small parts to re-install them. I took them off before my trip, due to noise from a loose brake shoe. |
JRV (Jrvall)
Junior Member
Username: Jrvall
Post Number: 216
Registered: 11-2002
| | Posted on Saturday, November 30, 2002 - 12:06 am: | |
If it turns out to be the diff housing make sure you replace it with the 512M part...the factory changed the design because the welded area turned out to be to brittle to handle the loading...the changed it with the 512M to a fully machined piece. |
JRV (Jrvall)
Junior Member
Username: Jrvall
Post Number: 215
Registered: 11-2002
| | Posted on Saturday, November 30, 2002 - 12:02 am: | |
Out of the left rear of the Trans Housing? or the left rear tire area?
If the diff housing cracks, the plates try to expand outwards placing pressure on the left trans sidecover. essentialy pushing on the carrier bearings....if you think it's in the tranny you'll need a mechanics stetoscope...you'll be able to here internal noises if that is in fact what's going on...are you sure it's not a parking brake shoe ? |
Henryk (Henryk)
Member
Username: Henryk
Post Number: 353
Registered: 8-2001
| | Posted on Friday, November 29, 2002 - 11:57 pm: | |
There were no oil leaks when I had the car on the lift. |
Henryk (Henryk)
Member
Username: Henryk
Post Number: 352
Registered: 8-2001
| | Posted on Friday, November 29, 2002 - 11:56 pm: | |
JRV: While coming home today, from Chicago, (about 250 miles), I heard a sharp, intermittent sound, about 50 miles from home......like a flat tire. I stopped, and saw no flat. I continued, with no sound......however, as I got closer to home, it started up again, and then went away as I let off the gas. It then came back on, but I was already at home.
Turning all the tires by hand, while on the lift, I heard a scraping type sound out of the left rear.
What gives? |
JRV (Jrvall)
Junior Member
Username: Jrvall
Post Number: 214
Registered: 11-2002
| | Posted on Friday, November 29, 2002 - 11:48 pm: | |
Was it making a noise while you were driving ?
The TR diffs Housings can/do crack , but generally not unless the car is doing burnouts or other extreme types of use. The welded side plate on the diff housings crack and can crack the trans sidecover also.
Have you been drag racing?
How cold is it there where you are ? |
Henryk (Henryk)
Member
Username: Henryk
Post Number: 351
Registered: 8-2001
| | Posted on Friday, November 29, 2002 - 11:40 pm: | |
I just came back from the garage.......couldn't wait!!!
In neutral, while holding one wheel, the other refused to turn.
In 3rd gear; Unable to move either wheel by hand.
Is there a probnlem?
|
JRV (Jrvall)
Junior Member
Username: Jrvall
Post Number: 213
Registered: 11-2002
| | Posted on Friday, November 29, 2002 - 11:28 pm: | |
It's fine, you have a Limited Slip Diff....they are supposed to turn together unless force is applied to the opposite wheel...then you will feel the drag of the spider gears and diff plates sliding. |
Steve Magnusson (91tr)
Intermediate Member
Username: 91tr
Post Number: 1210
Registered: 1-2001
| | Posted on Friday, November 29, 2002 - 11:28 pm: | |
Putting the car in gear -- i.e., coupling the transmission output shaft to the (stationary) crankshaft -- shouldn't prevent you from rotating a rear wheel by hand (if both rear wheels are off the ground). What it does require is that the sum of the rotations of the rear wheels always equals zero (which is why the other rear wheel will rotate in the opposite direction in this condition). |
Henryk (Henryk)
Member
Username: Henryk
Post Number: 350
Registered: 8-2001
| | Posted on Friday, November 29, 2002 - 11:14 pm: | |
By putting the car in gear, won't the engine prevent the ability to turn a wheel by hand? |
Steve Magnusson (91tr)
Intermediate Member
Username: 91tr
Post Number: 1209
Registered: 1-2001
| | Posted on Friday, November 29, 2002 - 11:09 pm: | |
I don't think so (unless there's a lot of unexpected friction in the spider gear mechanics). |
Henryk (Henryk)
Member
Username: Henryk
Post Number: 349
Registered: 8-2001
| | Posted on Friday, November 29, 2002 - 11:06 pm: | |
Thanks Steve: It is too cold to go out now, and try your suggestion.....I will try it tomorrow.
Is this any cause for concern? |
Steve Magnusson (91tr)
Intermediate Member
Username: 91tr
Post Number: 1208
Registered: 1-2001
| | Posted on Friday, November 29, 2002 - 11:02 pm: | |
It just shows that you have less friction in the transmission output/pinion shaft stuff than in the differential's spider gears (i.e., if both wheels are turning in the same direction then the ring gear is rotating the pinion/transmission shaft and the spider gears are not rotating). If you put it in gear (which couples the pinion/transmission shaft to the non-rotating crankshaft) the other rear wheel will rotate in the opposite direction (i.e., the spider gears will rotate). |
Henryk (Henryk)
Member
Username: Henryk
Post Number: 348
Registered: 8-2001
| | Posted on Friday, November 29, 2002 - 10:45 pm: | |
While having my car on the lift in neutral, I notice that while rotating one rear wheel, the other one rotates in the same direction.
If I recall, while turning one wheel in one direction, the other one turns in the opposite direction.
Is something wrong?......or is it just me?
Thanks |