Torque converter lock up
- Thread starter JJKM
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Datatek
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Too early for me to know, but does it actually have torque converter lock up? Certainly my old Daimler Jag did not have lock up.
norseman
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The ZF 'box should up-shift into 4th (overdrive) gear & lock the converter at around 50 mph, if my memory serves me correctly.
If you give it some welly above that speed (but NOT enough to activate the kick-down) the revs should only increase proportionally with the road speed, indicating that the TC lock is engaged. My '87 locks at 40mph but there's not a great drop in revs. as the 'box is only up-shifting into overdrive.
If you haven't already done so try checking the transmission fluid level (transmission cold, engine running & 'box in Park, after shifting through the gears first) & it's very important that the car is level when doing so. If the level is low only add small amounts at a time, you don't want to overfill.
'Oh & look at the fluid colour on the stick as well, crimson is good, slightly brown still ok, dark/black (& smelling burnt) you've got problems
If you give it some welly above that speed (but NOT enough to activate the kick-down) the revs should only increase proportionally with the road speed, indicating that the TC lock is engaged. My '87 locks at 40mph but there's not a great drop in revs. as the 'box is only up-shifting into overdrive.
If you haven't already done so try checking the transmission fluid level (transmission cold, engine running & 'box in Park, after shifting through the gears first) & it's very important that the car is level when doing so. If the level is low only add small amounts at a time, you don't want to overfill.
'Oh & look at the fluid colour on the stick as well, crimson is good, slightly brown still ok, dark/black (& smelling burnt) you've got problems
Henry_b
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Oh just to add when topping up it's around 250ml between Min and Max so don't drop a drum in there
You should have 4 gears and a "lockup"
At 60mph she should be at around 2100rpm..
You should have 4 gears and a "lockup"
At 60mph she should be at around 2100rpm..
discool
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If, you have a “4 speed” box then you have four ratios, if you are on a light throttle then the TC will lock at around 53ish mph, the older RR box, that I had once, was around 45ish mph and a bit of a pain for me being that low.
Anyway, if u forget the light throttle and carry full throttle acceleration and the TC won’t lock up, but will as soon as as u ease off.
RAVE has all the info for change points and vehicle speeds that ratios will change both up and down and the max speed for ‘kick down’ and TC lock to operate 85mph iirc.
Henry_b
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never heard of anyone worrying about a gearbox being smooth lol
discool
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RAVE states that 4th ratio engagement is simultaneously with TC lock therefore u won’t feel the engagement thats why moving into at higher ratio the engine revs drop. Try selecting position 3 from D at 40/50 mph so before the TC is locked and see the engine revs rise, so what I assume is now 3rd due to the vehicle speed, as I’m sure u know position 3 you can be in any ratio other than 4th.
I have never felt 4th engage, if any thing it would be first to second, depending on the variables of road and road speed on both my old RR and now a D1.
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Model 35 box fitted to that. At least you could bump start it.
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Are the throttle and kickdown cables adjusted correctly?
Datatek
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Aye, 2 oil pumps, one on the input shaft and one on the output shaft
norseman
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That's correct, 4 ratios with TC lock-up on 4th which is an overdrive ratio.
Starting in first you will have 3 up-shifts as you describe.
The 'box can be a bit inflexible at times ie on the rare occasion I need to floor mine exiting a roundabout (with 'white-van man' up my backside) the 'box will hold onto 2nd gear to quite high revs. but will up-shift to 3rd & immediately into 4th when I ease off the throttle.
The alternative of course is to hold the gears by using the stick shift, although that won't prevent down-shifts at the appropriate road speeds.
I like my old '87 changing into o/d at 40 on a normal throttle, with the country lanes around here it makes for a relaxed & (relatively) economical drive
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