A340 / A343 auto issues

User avatar
kbushnz
Hard Yaka
Posts: 2486
Joined: Wed Sep 16, 2009 9:03 am
Location: Massey, Auckland

A340 / A343 auto issues

Postby kbushnz » Sun Sep 03, 2017 11:25 am

Hi Yah Guys and Gals.

Got a funny issue with my auto...
I think I know what it is but thought I would share and see if anyone else could offer some insight.

Firstly some history...
Its in a Prado KZJ78...
Manualised... (no ECU)
Had transgo kit fitted.
Torque converter overhauled.

Its been off the road parked up for 3 years while doing my body chop and recert.
Fresh trans fluid...
The oil pump was removed to allow me to change the bush in the front where the TC runs as it was cracked.
Assembled with new TC.

Ok here's the issue.
Drives off the mark ok...
But when in any gear it just fares out. Anything above 2200 ish rpm when you accelerate moderately it jumps up to 3000 ish before it really starts to bite and pull.
If I lock the TC it pulls hard and feels great.
Stall test is good....
So something in the TC circuit it not right.
I have eliminated a clutch pack issues as talking with a trans shop it would have destroyed them by now with the amount of driving its done. (over 1000 ks inc a brake test and off road day trip)
I suspect my oil pump removal has done something funky as it wasn't like it before it went in the garage 3 years ago...

Am I on the right track.... anyone else had similar issues in the past...

I am going to drop the box next week and do some investigating.
Possibly damage seal when I installed pump.
Bush I replaced is too big and letting fluid past too much.
Something else in the the auto is bleeding fluid. Gasket let go in control pack.

Calvin
Cheers Calvin
KZJ78 Landcruiser Prado...

BlakeNZ
Hard Yaka
Posts: 710
Joined: Sun Jun 16, 2013 10:50 am
Location: manawatu

Re: A340 / A343 auto issues

Postby BlakeNZ » Sun Sep 03, 2017 8:06 pm

Just checking...are you familiar with the three stages of sliding the torque convertor on to the A340 shaft? ( first spline, second spline, then the notches?)

User avatar
Crash bandicoot
Hard Yaka
Posts: 2924
Joined: Thu Dec 30, 2010 7:19 pm
Location: Towing a hilux

Re: A340 / A343 auto issues

Postby Crash bandicoot » Sun Sep 03, 2017 8:22 pm

If its not the tc pump engaged properly then the next would be the line pressure dropping.
Waiter...there is a drought in my glass.

User avatar
kbushnz
Hard Yaka
Posts: 2486
Joined: Wed Sep 16, 2009 9:03 am
Location: Massey, Auckland

Re: A340 / A343 auto issues

Postby kbushnz » Mon Sep 04, 2017 7:22 am

BlakeNZ wrote:Just checking...are you familiar with the three stages of sliding the torque convertor on to the A340 shaft? ( first spline, second spline, then the notches?)


Yup fully aware of that one....
The trans won't actually bolt up to the engine if its not snuggled into place.
This auto has been in and out several times over the 17 years I have owned it lol.
Cheers Calvin
KZJ78 Landcruiser Prado...

User avatar
kbushnz
Hard Yaka
Posts: 2486
Joined: Wed Sep 16, 2009 9:03 am
Location: Massey, Auckland

Re: A340 / A343 auto issues

Postby kbushnz » Sun Sep 10, 2017 3:13 pm

Auto dropped, pump checked out good. Clutches all good. Oil all good.
Pulled valve body apart and had some silver looking oil in 2 spots in the galleries. Looks like the oil has been bypassing the gasket.
Clean and New gaskets.. Put together with new oil and now drives much better.
It's got bite now where it had sweet F all before.
Suspected pressure leak to the torque converter charge circuit.

Will give it death and if it goes bang there is a 5 spd waiting for it.

Calvin
Cheers Calvin
KZJ78 Landcruiser Prado...

Return to “Toyota”

Who is online

Users browsing this forum: No registered users and 13 guests