Auto gearbox stuck in lower gears

Technical questions and answers about the Mazda Bongo

Moderators: Doone, westonwarrior

Post Reply
User avatar
JimLad
Apprentice Bongonaut
Posts: 9
Joined: Mon Jul 27, 2020 1:25 pm
Location: Reading

Auto gearbox stuck in lower gears

Post by JimLad » Wed Sep 02, 2020 12:57 pm

Hi Bongo people, I wonder if you can help me...
I have a 2.5TD Auto from 1997 and I'm having a problem with the auto gear box.
Basically the gears are sticking as I get to 2nd or 3rd, and also randomly change down to 2nd sometimes when I pick up speed on perfectly flat roads.
It seems to only happen for the first 10 minutes or so of driving, and I'm forced to use the 'Hold' function to force it into 3rd once I pick up speed. After a while it seems to fix itself. (I am using 'D' by the way)
I've checked the transmission fluid and it's full and clear pink. I will probably end up taking it to a garage, I just wanted to know what you guys think.
Thanks!
Bob
Supreme Being
Posts: 15255
Joined: Wed Oct 17, 2007 12:54 pm
Location: North Somerset

Re: Auto gearbox stuck in lower gears

Post by Bob » Wed Sep 02, 2020 2:26 pm

Hi, and welcome aboard.

Don't want to teach you to suck eggs, but did you check the fluid level with it hot, and with the engine running, after cycling the selector a few times?
User avatar
JimLad
Apprentice Bongonaut
Posts: 9
Joined: Mon Jul 27, 2020 1:25 pm
Location: Reading

Re: Auto gearbox stuck in lower gears

Post by JimLad » Wed Sep 02, 2020 10:22 pm

No no, please teach!
I know nothing about these things.
I tried when it was still warm and running, maybe I'll leave it on for longer and move the selector before trying it again. (you mean the gear selector right?)
Thank you for your reply.
Bob
Supreme Being
Posts: 15255
Joined: Wed Oct 17, 2007 12:54 pm
Location: North Somerset

Re: Auto gearbox stuck in lower gears

Post by Bob » Wed Sep 02, 2020 10:25 pm

Yes.

Engine up to full temp, park on level ground, cycle gear selector (gently) a few times, then remove dip stick with engine still running.

It can be tricky to spot the level. :wink:
Ian
Supreme Being
Posts: 5885
Joined: Wed Jun 09, 2004 2:47 pm
Location: Bongo Mission Control

Re: Auto gearbox stuck in lower gears

Post by Ian » Wed Sep 02, 2020 10:41 pm

Also sniff the ATF. If it smells like burnt toast it needs replacing.

Here's some other things to check (copied from the "Juddering" fact sheet in the members area of main website)

Not all gearbox problems are actually gearbox problems at all. Lots of things affect when the gearbox changes, including the fuel filter, banjo filter (top of the fuel pump), throttle position sensor, and turbo pipework leaks. All these can fool the gearbox into conflict.

Assuming it’s none of the above, then look at these queries from the Bongo Fury Forum.

“In the last couple of days, my auto-gearbox seems to have developed problems, especially between first and second gear. Sometimes I get a judder when pulling away from a standing start; at other times when I am in slow moving traffic and go to speed up the engine revs too high. On other occasions when it attempts to change between first and second it takes a few seconds and then changes with a big jolt. Any clues?”

This sounds like the forward clutch is starting to slip.

“I have a 2002 bongo with 85,000 miles on it. Standard 2.5d. I’ve just replaced the transmission fluid pipes on my Bongo after a fluid leak at a garage here in Brecon. As a result of the leak I had no gear engagement at all but did manage to crawl 150m to park up before arranging recovery. After being fixed, when I’m travelling at a very slow speed turning left or right, or starting off (not all the time), first gear does not engage straight away and I get a judder when it does. What do you reckon?”

Assuming your oil level is correct, you may have damaged your forward clutch by driving it slipping. It only takes a few yards to total a slipping auto clutch. I take it the judder isn't a Limited Slip Differential (LSD) judder from the rear axle when cornering?
668. The Neighbour of The Beast.
User avatar
JimLad
Apprentice Bongonaut
Posts: 9
Joined: Mon Jul 27, 2020 1:25 pm
Location: Reading

Re: Auto gearbox stuck in lower gears

Post by JimLad » Thu Sep 03, 2020 2:27 pm

Thanks for your replies, really good info there.
I have a hunch it may be the throttle sensor.
The gear changes themselves sound fine, it just takes way more speed sometimes to get it to change up.
I've only had the van since March, and it only started doing this recently.
The only thing I've changed on it is the speedo.
User avatar
g8dhe
Supreme Being
Posts: 10180
Joined: Sun Apr 13, 2008 10:06 pm
Location: Worthing, West Sussex.
Contact:

Re: Auto gearbox stuck in lower gears

Post by g8dhe » Thu Sep 03, 2020 3:00 pm

When you say you changed the Speedo what exactly did you change ?
There are 6 outputs from the speedo to all sorts of things including the ECU and hence the gearbox, see top and left of the diagram;
Geoff
2001 Aero V6, AFT, full side conversion.
Image Spherical Visions
User avatar
JimLad
Apprentice Bongonaut
Posts: 9
Joined: Mon Jul 27, 2020 1:25 pm
Location: Reading

Re: Auto gearbox stuck in lower gears

Post by JimLad » Tue Oct 20, 2020 4:10 pm

Just the faceplate to one that reads in mph. Although I had to take a lot of it apart to get to it, I'm pretty certain that I put everything back together as it was.
(Sorry for the delayed reply)
tuvster
Apprentice Bongonaut
Posts: 5
Joined: Mon Nov 08, 2021 7:01 pm
Location: Cwmbran , south wales

Re: Auto gearbox stuck in lower gears

Post by tuvster » Mon Nov 08, 2021 7:08 pm

JimLad wrote: Wed Sep 02, 2020 12:57 pm Hi Bongo people, I wonder if you can help me...
I have a 2.5TD Auto from 1997 and I'm having a problem with the auto gear box.
Basically the gears are sticking as I get to 2nd or 3rd, and also randomly change down to 2nd sometimes when I pick up speed on perfectly flat roads.
It seems to only happen for the first 10 minutes or so of driving, and I'm forced to use the 'Hold' function to force it into 3rd once I pick up speed. After a while it seems to fix itself. (I am using 'D' by the way)
I've checked the transmission fluid and it's full and clear pink. I will probably end up taking it to a garage, I just wanted to know what you guys think.
Thanks!
Hi just started developing an issue with my freda , had a new fuel pump fitted , got it back and the gears seem strange now , going from 2nd to 4th pretty much missing out 3rd , having to use hold more than i ever have , wondered if anyone can help? the fluid is new by the way

EDIT
Duplicate post here viewtopic.php?f=3&t=78151&p=720765#p720760
User avatar
JimLad
Apprentice Bongonaut
Posts: 9
Joined: Mon Jul 27, 2020 1:25 pm
Location: Reading

Re: Auto gearbox stuck in lower gears

Post by JimLad » Thu Nov 11, 2021 10:43 am

tuvster wrote: Mon Nov 08, 2021 7:08 pm Hi just started developing an issue with my freda , had a new fuel pump fitted , got it back and the gears seem strange now , going from 2nd to 4th pretty much missing out 3rd , having to use hold more than i ever have , wondered if anyone can help? the fluid is new by the way
My problem seemed to just fix itself after it's last service.
Mechanic said the fluid was fine but I got him to change it anyway. Only other thing of note was that my radiator was massively blocked with leaves, so I cleared that off. It was still playing up for a week or so and then never happened again. 🤷🏻‍♂️
I don't know if we had the same problem, my gears were also jumping down at random times. Like the engine was struggling for some reason and just telling the gearbox it needed more revs.
That's my story anyway, hopefully one of the experts on here will be able to give you more insight.
tuvster
Apprentice Bongonaut
Posts: 5
Joined: Mon Nov 08, 2021 7:01 pm
Location: Cwmbran , south wales

Re: Auto gearbox stuck in lower gears

Post by tuvster » Fri Nov 12, 2021 7:52 pm

Thanks jim
oibaf
Bongolier
Posts: 153
Joined: Sat May 08, 2021 8:11 pm
Location: Ireland

Re: Auto gearbox stuck in lower gears

Post by oibaf » Tue Nov 16, 2021 11:54 am

I don't have much to add but, did the Hood light flash on the dash? Did you read the codes if so?

There's a handy guide to that here http://www.philmcfadden.co.uk/MazdaDiagnosticBox.htm
Post Reply

Return to “Techie Stuff”