2l engine auto gearbox woes help/advice please

Just have your cheque book ready ... mine went in with an oil leak... came out fully rebuilt.... Bank account £2400 lighter.
Did a good and quick job ... runs so much better now.

 

The auto box has an oil leak somewhere. Maybe we should clean it up and drop the atf sump and inspect the strainer. We have a new gasket seal in anticipation. Is there a drain plug on the auto unit like the separate diff or do we just undo the sump bolts and drain it that way. We have new correct red atf. We also have new GL4 for the diff so will do both. Is there a diff oil drain plug, I see the filler/level plug ok.

Good point about the engine revving but not a lot of power. How do we check its firing on all 4, temperature check of rocker covers? Or could we use a strobe light on each plug lead?

We have a compression tester so will check compressions.

Re on road performance yesterday, it was slow and sluggish on the flat and going up a hill my son had to select first and floor it to get it to the top of the hill and only managed 20mph. I am not driving it myself yet, its too scary.

 

The previous T25 is still with us and when we get time the intention is to remove the engine and manual box which are both good. Its pretty much stripped out now and eventually the shell will go to scrap or give it away.

 

Just change the bloody filter and ATF and take it from there. The day you bought it I suggested doing that so hopefully your mechanics have done so and eliminated obvious and visual issues. It's a cheap first step...unless of course the PO already got rid of the evidence.....xx

 

My auto box was rebuilt for around £350 cash by an old boy who used to specialise in them and he has a ton of hard to get NOS parts. Make sure that the throttle linkage is correctly tensioned between the pedal and the box and then from the box to the carb linkage. Get someone to push on the peadal while you check. If it is an 010 I've attached the manual.

 

That trouble shooting guide will really help these guys .
Irregular movement...blocked strainer possibly...gotta be worth a look

 

They have to drop the sump off the transmission to replace the internal filter, thus renewing the fluid at the same time. Also levels and filling are very specific.
Just check what they've actually done Alex as I'm as confused as you are lol.
Will we see you this week for a cuppa?

 

Filling with ATF is done through the dipstick tube I assume. Also does the diff have a drain plug as I want to change the GL4 oil as well.

 

AFAIK, there is no drain plug on the differential. There is a 17mm hex fill.
Normal procedure would be to siphon as much oil out of the differential housing as possible through the fill plug, then drop the pan.
Remove any debris, replace gasket and refill the diff casing with the appropriate quantity and grade of diff oil.
The actual gearbox is filled with ATF via a funnel through the dip stick.
But this is a much more specific process involving several steps to ensure exactly the right quantity is used.
You really need to read Bentley, the file that @Fruitcake linked and look up the Samba.

 

Spot on Neil, it's easy to overfill. @mgbman have a look at this link, about halfway down there's a picture of the 'box and a good description of how to drain, clean the filter and refill.

 

I didn't have much time to read so don't flame me but why do you think its the box? I read fuel somewhere in this post.

The auto 010 boxes aren't super complicated (and are mechanical not vacuum as someone said) and about the only thing that can go wrong with torque converter is seal which is the most likely cause of your leak.

I'd make sure its got a clean petrol and 110% check/change the fuel filter, check all plugs, everything etc are correct (so a service & oils + filters) change your plug leads then do some compression tests. Does the T25 have a TII sensor ? I don't know but if it does a new one of those wouldn't be a bad change.

The box only responds to the power from the engine so if there was no power from the box to the wheels but engine was ok then I would expect high revs but you say engine dies or cannot tick over when it goes into gear, not sure thats all due to the box.

ATF you have to check when engine is warm but oil you check when cold. Tappets etc all cold.
Good luck with it (and sorry again if I missed some info in the thread).

PG

 

Thanks for the ideas and help so far. I think the main clue out on the road is the engine not revving as it should using the pedal. In the engine bay the engine revs freely by manually using the balance bar but won't out on the road so the throttle cable is a suspect. Maybe the carb butterflies are not opening fully or carbs need servicing. We will see.

So lots to do at the weekend. I will focus on the engine first and sort out the pedal and any throttle cable issues. Engine needs new leads and plugs and I will do compression tests. Oil and filter was changed recently. Couldn't find a fuel filter so I will fit a new one after the tank outlet.

With the air filter off I will check the carb butterflies open fully and properly using the pedal. Both chokes work correctly and open after a few minutes.

The fuel tank is old and crusty and may well have rust in the fuel. My son has removed the tank and fittings from the old T25 and those items are quite new and the tank is clean and painted. So we have plenty of spares from the old van.

My son said the new van was difficult to start, even when all earth straps were cleaned up. It has a new looking starter motor. The solenoid connections were cleaned up and the trigger wire spade soldered. I found the battery negative cable to the body was getting hot when trying to start it, so changed that for a new thicker cable and the engine now starts straightaway.

I did screw in both throttle stop screws on the carbs to get the engine to idle in neutral but not tinkered with anything else on the carbs.

I will drain and change the atf and diff oil and we have a new box oil pan seal and internal filter.

So lots to do.

 

Another point which may prove significant is my son did say that a few weeks ago he thought the mechanical fuel pump may be failing to deliver fuel and he bought a replacement push rod as the old one was worn down. But that may not have fixed the problem.

Probably a case of throwing new parts at it without finding the actual fault, which may not be fuelling at all.

Out on the road the engine did not cut out or misfire, it just ran slow revs so insufficient power to go up the hills.

So I think at the weekend I will focus on the engine, fuelling, compressions, ignition and so on so it starts, revs freely and idles correctly.

 

Impossible to be sure but my money would be on the engine running on three cylinders. Renew the plugs and make sure the firing order is correct – it’s easy to get it wrong.

 

You said you drove up a hill in 1st at 20mph - did you try and put it in second once you got going? The low revs and failing to change down sounds like the box to me.

 

'...when in drive and on the road it runs very very slowly at no more than 20mph with pedal to the floor and the engine seems to be revving slowly and its a struggle to get up hills even when in first gear. Sounds like engine to me. In first gear it should rev its nuts off.

 

What if it's simply not changing down? From the below it sounds that way, it should have changed down on it's own?