₦airaland Forum

car-doctor:
Automatic gearbox issues have become a reoccuring decimal to any automatic car owner. Slow take off, sluggish acceleration, lack of kick down, loss of drive while in motion, lack of gear change, aggressive gear changes, high engine revs without power in drive just to name a few.

From my observation and the complaints made by some of our customers, these problems usually start from a gearbox oil change that was recommended by the mechanic who then uses the wrong type of ATF oil for the transmission.

Most car manufacturers develop their own ATF formular for their cars.

Honda recommends their own formular ATF-z1 for their gearboxes manufactured between 1998 to 2009 and upgraded to the ATF-Dw1 for gearboxes manufactured from 2010 upwards.

Toyota uses the Type 4 ATF for their cars manufactured between1996 to 2007 and the Toyota WS ATF for ones manufactured between 2007 to present.

Most other car manufactures have also upgraded the type of ATF for their modern cars.

Using the wrong grade of ATF would almost certainly result in a failing transmission. Low grade ATF may not be able to handle the high temperature operations operations of a gearbox. Under very high temperatures, low grade oil loses its fluidity and may begin to boil causing loss of hydraulic functions by frothing or foaming.

Some remedies I have seen used by local mechanics is to further add engine oil to the gearbox in order to thicken the viscosity of the ATF. This in turn puts the pump under great stress as the thicker oil would require more effort from the pump in distributing the oil under high pressure as well as the oil filter which is usually embedded within the transmission gear train. (The removal and changing of all Honda transmission oil filter would require the removal of the gear box from the car and stripping down the gearbox)

The resulting consequence would be an imminent and extreme overheating of the transmission and components such as the friction plates and a rapid degradation of the wet clutch fibres hence the loss of drive, slipping clutch and rough gear changes.

Replacing the gearbox or a total overhaul by an expert would be the likely solution but before then, an inexperienced mechanic would Send you on a wild goose chase by suggesting the removal and servicing or outright replacement of shift solenoids on the outer casing of the gearbox. These solutions Don't last as its just a temporal remedy to a terminal issue.

We constantly repair these gearboxes and those of other makes to a very high standard with 99.9% success rate and we recommend that if you are having serious issues with your automatic gearbox, ensure that the appropriate procedures are followed.



Car-Doctor.

Hi Car-Doctor
Thanks for this page. You seem experienced and knowledgeable. I live in the US and just got a 2002 accord accord few weeks back from a dealer here but I have some problems described:
(1) I feel an annoying jerk each time I come to a full stop with my foot on the brake pedal. The jerk is a little milder if I decelerate gently.
(2) I feel the same jerk if I put my car in drive (D4) from P or R. Jerks not noticeable when I put in R from D or P.
(3) I feel some vibrations at a stop with the car in gear and my foot on the brake. Gets scary if AC is on. For this I just got my right rear motor mount replaced (which the mechanic told me was broken). Vibrations still there but only reduced.
I had the thought that my transmission might be having issues so I recently drained the fluid to replace with ATF-DW1. No improvement. I don't know if I need to do this again.
It might sound strange that I'm contacting you from the US. Like I said, I get the impression that you know what you are talking about, unlike the majority here. I've been to different auto shops here, leaving more confused. Each gave different diagnostics. I've spent a lot as well just to find out what the problem might be. PLEASE HELP as soon as you can.
Thanks

OgbeniDudu