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Lag engaging gear

4K views 15 replies 5 participants last post by  Jean7 
#1 ·
Hi again

Thanks so much to those who helped with the fuel pump question, especially Steve.

Now that 37889 is going again I am reminded of an old problem, that when I select Drive or Reverse, there is a lag of a couple of seconds before it engages. Is this a feature or a problem?

Many thanks,
Peter
 
#2 ·
Check trans fluid level. Drive the car for at least 20 min. Leave car running in Park and engage parking brake. Pull A/T dipstick out, wipe clean and re-insert. Check the level against the dipstick markings.
When was the fluid changed?
 
#4 ·
Hi Wraithman,

Thanks for your reply. The transmission fluid hasn't been changed for a long time as the car has been idle and I'm only just getting it up and running again. It's a bit dirty but not awful.

I checked the level cold, it was very low, almost off the tip of the dipstick so I put some Dexron II into it even
before running it, and the level rose to about 1cm above the tip of the dipstick, still way below the minimum level.

I then drove the car for 2 miles and noticed smoke. The transmission fluid dipstick had been pushed up and a splatter of transmission fluid went over the area including the exhaust manifold, hence the smoke.

I let it run another 20 mins and checked the fluid level. It was still low.

What do you recommend?

Peter
 

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#5 ·
You either overfilled or underfilled. Must be checked hot, running and in Park. I suspect that it was low from the start, but it is still a guess
So again, check when hot. It is highly likely the filter is clogged after all these years and a simple drain, re-fill and filter change will return things to normal. The TH400 is extremely durable and easily serviced, but like any transmission, there is maintenance.
There are 4.5L used when draining the sump and trans filter change.
 
#8 ·
Do not forget to replace the main rubber sump gasket.
There are kits

If I were you, I will drain the sump, then collect also oil in the sump, then mesure the old oil quantity.

Then , after cleaning and putting a new filter, I will add about 4 liter max, rather 3.7, and start the engine and let it warm iddling, and after at least 20 mn check trnamsission level and add very slowly and check.
It make take an hour to make the right level, too much is very bad, destro trnasmission.

Then you drive about 20 km and check the level again, iddling and adk=just if necessary.
 
#9 ·
Note: The gearbox pan is stamped steel. Careful tightening of the bolts to spec and doing so in a cross-wise pattern will help prevent leakage from the seal. You may also find a magnet in the pan. It is there to collect metal sludge that develops with gear mesh applications.

Also, the filter floats on the bolt that holds it in place. It is a shoulder bolt that will tighten and allows movement of the filter. Replacement of the "O" ring on the suction tube is important not allowing air to be sucked up. Also, remove most of the pan bolts and keep 2 on the final edge allowing the pan to slightly hinge down to drain. When removing the filter more fluid will be released.
Changing the fluid in an automatic is rather messy and careful prep is in order. Clay kitty litter can be helpful.
 
#10 ·
just to add to the helpful information you have been given. you say the fuild looks dirty is it red or dark brown and does it have any smell to it? as to the oil coming out of the dip stick hole if the dip stick is not all the down this is normal.the oil is being pushed and pulled and at high pressure, this will cause it to heat up and expand and why there is an oil cooler for it as well and why you should only top up when it hot
 
#12 ·
Low fluid will be even lower as the transmission warms up. Fluid gets pumped into the torque converter. My guess is that your issue comes from 2 distinct problems: low fluid, and moisture in the old fluid. A thorough service and getting the level up to par will virtually eliminate the likelihood of a mechanical issue. Of course an electrical issue could still exist.
 
#13 ·
The only electrical connections is a kickdown solenoid and a pulse transmitter fitted to the speedo shaft. Earlier cars used a speedo cable, hence there would be no "connection" between the problem as reported.
Stay on course with a new filter and refresh the fluid.
 
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