Auto Box Trouble!!

rontrousers · Post by **rontrousers** » Thu Nov 23, 2006 7:23 pm

I'm having the following problems with my autobox.

In addition to the box not wanting to change from 3rd to 4th when cold (and 2nd to 3rd when very cold), i appear to have gained an extra gear between 3rd and 4th!!!

On changing from 3rd to fourth (usually happens at between 40 and 50 mph on the flat) the the enging revs drop (as expected when changing gear), but after a afew second the engine revs drop again as 4th is finally found.

During this "extra gear" I'm able to press the accelerator to increase engine revs without changing road speed.

A similar affect happens in reverse when the box drops from 4th when accelerating.

Any help/advice would be appreciated.

DemonAV · Post by **DemonAV** » Thu Nov 23, 2006 7:53 pm

You have Not problem.

1) When autobox oil is cold, speed do not change on 4-th gear thus far oil it will not be heated above 10 degrees Celsius
2) on 4 gear occurs blocking hydraulic converter, this you assume as the complete found 4 gear

I can sufficiently in detail describe this in the Russian, but possibly I entirely correctly did not explain in the English

ferdyb · Post by **ferdyb** » Thu Nov 23, 2006 8:12 pm

Demon is right, you don't have a problem, the box waits until the whole lot gets a bit of heat into it before it allows the gears to engage at their normal road speeds. When the rev counter ceases to show flexibilty as you say, and goes 'solid' is when the 'overdrive' engages and locks the torque converter and gives you 25mph/thousand revs.

The Bongo has four gears and five ratios.

ferdy

rontrousers · Post by **rontrousers** » Thu Nov 23, 2006 8:20 pm

Thanks for the reasurance.

Just to confirm the 3rd to 4th issue occurs even when fully warmed.

white van man · Post by **white van man** » Thu Nov 23, 2006 9:12 pm

check fluid level and smell to see if it smells burnt ,if it does do a fluid and filter change but it may be to late and box might need overhaul

rontrousers · Post by **rontrousers** » Thu Nov 23, 2006 9:42 pm

Oil seems OK and between max and min marks when hot.

A filter and oil change would probalbly sort the late changing when cold.

I appreciate the reasurrance given about the third to fourth change, but the problem would persist for miles if I didn't ease off the throttle. On a roundabout recently, i narrowly avoided collision from another vehicle. When I put my foot down, it had no effect for probalbly nearly a second.

dandywarhol · Post by **dandywarhol** » Thu Nov 23, 2006 10:06 pm

Sounds like an oil change is due. The recommended intervals are 24,000 miles.

The filter is a gauze type and can get a bit clogged. I cleaned mine the other day, the sump pan and magnet were a bit sludgy. A good clean and filter cleaned with parts washer and thoroughly dried off and fresh oil has speeded up my gearchanges.

rontrousers · Post by **rontrousers** » Thu Nov 23, 2006 10:57 pm

I'll get on with an oil change this weekend. What's the chances of breaking the gasket when removing the sump?

Cheers

Martin

dandywarhol · Post by **dandywarhol** » Thu Nov 23, 2006 11:52 pm

I've only dropped one Bongo sump and the gasket was undamaged so I'd say ermmmmmm.........50/50...........

Veg_Ian · Post by **Veg_Ian** » Fri Nov 24, 2006 1:22 pm

Problem with this is that you can't get the fluid out without dropping the sump. It's heavy when it drops as it's full of fluid. Not easy to steady it if laid on your back with the vehicle on stands. Anyway, anticipate the gasket breaking. I replaced mine with a silicone based gasket sealant (forget the brand, could have been haematite). Worked a treat. Hardest job was cleaning the paving blocks afterwards

rontrousers · Post by **rontrousers** » Fri Nov 24, 2006 6:26 pm

Great, thanks for that bit of advice.

Instant gasket and a gallon of drive cleaner.

Cheers

Martin

Simple Simon · Post by **Simple Simon** » Fri Nov 24, 2006 6:56 pm

rontrousers wrote:A similar affect happens in reverse when the box drops from 4th when accelerating.

Blimey, I thought that you had the Italian army version for a minute!!!

dandywarhol · Post by **dandywarhol** » Fri Nov 24, 2006 7:01 pm

Veg_Ian wrote:Problem with this is that you can't get the fluid out without dropping the sump. It's heavy when it drops as it's full of fluid. Not easy to steady it if laid on your back with the vehicle on stands. Anyway, anticipate the gasket breaking. I replaced mine with a silicone based gasket sealant (forget the brand, could have been haematite). Worked a treat. Hardest job was cleaning the paving blocks afterwards

Be very, very careful with the instant gasket - I used to overhaul auto boxes and saw the damage done when tiny particles of silicon goo got into the valve block valves

shakey · Post by **shakey** » Fri Nov 24, 2006 9:24 pm

Ron, just a thought before you drop the trans. pan, are you testing your transmission fluid with the engine running, or switched off? If the latter, try seeing how much the stick shows when running, you might be low on fluid. Shakey.

rontrousers · Post by **rontrousers** » Fri Nov 24, 2006 10:08 pm

Thanks for the info gents.

I've checked the level with the engine running. I'm now in a bit of a dilema.

I've only had the bongo a couple of months, and I took it back to the garageI bought it from to sort out under their warranty. They appear to be unable to repoduce the cold gear change problem. If I drop the oil myself and there's a subsequent problem, I can't help feeling I'll be on my own.

Anyone able to suggest an auto specialist in the swansea area?

Ron.

Auto Box Trouble!!

Auto Box Trouble!!

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