Outer Limits 4x4 Board

i have a slight problem with my auto trans which is up behind the V8..... on the highway when you first get to 90kph on the speedo (it's actually doing about 96) it drops into overdrive like it's supposed to, but it does it slowly compared to how it used to. After about 10 seconds it comes out of overdrive and stays out until after i stop and start the car again obviously to reset the transmission ECM. I have the TPS mounted in the car, and it's in a position where it drops into overdrive, so it's not wound round too far, other than that, nothing has changed. The gearbox wasn't even moved when the conversion happened. I did have the trans oil running through the old aircon condensor..... i changed it to a small purpose made trans cooler.... still no difference..... I don't mind driving it around in 4th gear, but some have said it overheats the gearbox... and i have a 5 hour drive to Rover Park in 3 weeks time

Any ideas?

TIA

From a different thread .........

RoeDao wrote:I have to utilise the throttle position sensor from the Patrol carby, in my engine swap.... a few people are of the opinion that i can use it like a dial in set up to fool the gear box as to how much throttle i am using... so it will short shift for traffic or fuel economy, or wind it up so it thinks i'm under a bit of acceleration for the fun events like mud drags and shit like that. Anybody heard of it being done? or does the TPS actually work that way? If i can, i'm going to mount it on the dash, or behind it and put a dial on the front.

Have you been farking around with stuff ?????

what type of transmission is it?

popeye wrote:From a different thread .........

RoeDao wrote:I have to utilise the throttle position sensor from the Patrol carby, in my engine swap.... a few people are of the opinion that i can use it like a dial in set up to fool the gear box as to how much throttle i am using... so it will short shift for traffic or fuel economy, or wind it up so it thinks i'm under a bit of acceleration for the fun events like mud drags and shit like that. Anybody heard of it being done? or does the TPS actually work that way? If i can, i'm going to mount it on the dash, or behind it and put a dial on the front.

Have you been farking around with stuff ?????

no..... all i have done is move it into the cabin, and extended the wiring. I know it's wired ok... because i can make it shift lazy, or hold the gears for extended periods by turning the knob in either direction. Other than that, i haven't touched a thing on the trans. Kickback on the accelerator works, and if i'm driving along at 60kph, and turn the TPS to the left, it will drop back a gear or two without pushing the accelerator.

Modified Toy wrote:what type of transmission is it?

Nissan electronic 4 speed auto.

probably 4th in the box is not to good as the tps should be mounted on the accelerator pedal as it measures engine load and adjusts line pressure in the box to suit via the vaiable pressure solenoid .so if the tps is miss adjusted at all trans will run low line and the box will burn.

but the only way i think you could run it the way it is is to run it inconjunction with a guage taped into line pressure aswell.

but usually slow into overdrive is caused by the band trying to slow the drum it is applied to

1. slipping due to bad adjustment.2 low line pressure 3.the band lining is badly burnt and can't stop the drum any more 4 could be the clutch that is applied on the 3-4 shift also

what is the 1st to 2nd shift like that same band is used for that shift.

Modified Toy wrote:probably 4th in the box is not to good as the tps should be mounted on the accelerator pedal as it measures engine load and adjusts line pressure in the box to suit via the vaiable pressure solenoid .so if the tps is miss adjusted at all trans will run low line and the box will burn.

but the only way i think you could run it the way it is is to run it inconjunction with a guage taped into line pressure aswell.

but usually slow into overdrive is caused by the band trying to slow the drum it is applied to

1. slipping due to bad adjustment.2 low line pressure 3.the band lining is badly burnt and can't stop the drum any more 4 could be the clutch that is applied on the 3-4 shift also

what is the 1st to 2nd shift like that same band is used for that shift.

the 1st to 2nd shift is ok...... sometimes 3rd to 4th is barely noticeable..... i will hook the TPS up to the throttle tomorrow night. This hopefully will solve it. I'm sure you are aware that overdrive is just a torque converter lock up....... it used to drop in readily..... so from what you are saying, it has to be the TPS position.

Spose you saw this:

screwy, as for the cooler don't use an old aircon core as i would have seen 4-5 boxs fail due to contamination. i cant tell you exactly why but they seem to have a film inside them and once mixed with ATF it just roots the box. as for converter i would go 2000-2500 in a good convertor not just a smaller one, something with modified vane angles, very driveable at 1200-1500, but will flash out to 2000 under big load. something like a TCI towing convertor. plus shift kit the box as it will give you better line pressure and will tend to hunt less in 2nd and 3rd.

no i hadn't seen that.... but oddly enough there was one site i saw on the net that said you can use the old aircon condensor. Luckily i guess that i haven't done a lot of miles with it hooked up. I'm going to pull it out this weekend to allow more air flow through the radiator and mount the trans cooler and an engine oil cooler in front of the radiator.

I'm sure you are aware that overdrive is just a torque converter lock up

Trans should have 1st 2nd 3rd 4th then lockup and in some conditions lock up will work in 3rd also inhibitor switch needs to be set correctly also.

Modified Toy wrote:

I'm sure you are aware that overdrive is just a torque converter lock up

Trans should have 1st 2nd 3rd 4th then lockup and in some conditions lock up will work in 3rd also inhibitor switch needs to be set correctly also.

where the kcuf is the inhibitor switch?

i hooked the TPS up to the throttle..... drives much better on the road..... haven't had it on the highway yet... will soon see tomorrow when i take it down to Athol to get it engineered.

the inhibitor is the switch that bolts on to the side of the box where the selector is

well, even with the TPS hooked up to the throttle, it won't hold overdrive for any more than 10 seconds first time it drops in. trans oil temp warning light came on twice in the 300+ k trip this morning, both times after loading it in 4th up hills. slowed down a bit, coasted down hills.... the light went out after about 5 minutes. In traffic, it works better if you hold the gears and shift manually.... I'm at a loss to work out whats the problem. i have to adjust the TPS a little because it's still shifting gears way too quickly. But it wasn't a lot worse than that with the nissan donk, and the overdrive worked on on that. I'll buy a carton for the first guy who can work out what the problem is.... i have got 2 weeks to get it sorted out

Low fluid level or burt out fluid

Guts wrote:Low fluid level or burt out fluid

i have been given a headsup by a friend that the most likely problem is it's in dire need of a service.... and the oil is probably rooted..... i'm going to book it in on monday for an urgent full service.

Fluid change will not fix problems have to get someone to look at the problem

what size tyres are you running and what ratio diffs ?

i also have the auto in my GQ, but its still running behind the facotry TB42, i have also noticed that recently it seems a little sluggish off the mark, and while on the highway it seems to shif out of overdrive also, but always shifts back in,

i would also appreciated any advice, especially if the auto trans service sorts out the problems,

i will garantee it has to do with the marks kit roedao the spacer you put in is slightly too small, i have had the same problem for a while upgraded the torque converter etc and my auto guy recons marks kit for the auto trans isn't done properly the only thing i have found is to put a switch on your lock up to lock it up manually or get a new spacer to size, and marks doesn't won't to know about it either

according to the comprehensive auto manual that a mate has.... it is supposed to be something to do with the oil being too old, the lockup valve and pilot blocked, apparently there is a filter as well (aside from the main trans filter). it notes the symptom to a tee!! exactly the same..... drops into overdrive and drops out again in less than 30 seconds. The first thing it says to do is to service the gearbox and change the filters. I'm hoping that is all it is..... the only way that thing will come off is to bolt a TH700 onto it. And i'll end up divorced before that happens

i was hoping a service was all it needed as well but i got a rebuild cause the auto shit it self behind the v8 and after the rebuild it was still doing it in the end i put a manual lock up on it

If the conversion setup isn't a perfect match for the auto trans, it's not hard to see how it could lead to more heat and poor auto trans performance.

I hate to say it but if you've just done an engine conversion and now your transmission is playing up, it is unlikely that it's just that the transmission needs a service.

Someone once told me that when something goes wrong with a car, you should always suspect the last repair job you did. I've found this to be true quite often.

chimpboy wrote:If the conversion setup isn't a perfect match for the auto trans, it's not hard to see how it could lead to more heat and poor auto trans performance.

I hate to say it but if you've just done an engine conversion and now your transmission is playing up, it is unlikely that it's just that the transmission needs a service.

Someone once told me that when something goes wrong with a car, you should always suspect the last repair job you did. I've found this to be true quite often.

it wasn't a gradual thing.... it just didn't work from the word go. The main concensus being that we contaminated the trans oil when we hooked it up to the aircon condensor. The trans oil itself is a horrible dark colour that was noticed during the engine swap... so it isn't because of it that it has gone the crappy colour it is now. We had hoses off, could have got dirt in the lines (careless i know) And when it first started playing up, i was driving steady, on flat ground (no real hills between here and the 35k drive to work) without any load on the trans. Who knows...... a service will be a start. If it comes to poking a TH700 on it, i'll worry about it then. 1,200 bux for a transfer adaptor and the G/B.. BAH! it's only money right?

And as i said in the previous post..... the full workshop manual for the trans explains the fault exactly and says what to do to rectify it... can only start there. As long as i can get a few more months out of it, and once the wife loses the phone number for the divorce lawyer.... i'll go from there

RoeDao wrote:
If it comes to poking a TH700 on it, i'll worry about it then. 1,200 bux for a transfer adaptor and the G/B.. BAH! it's only money right?

I am no expert, but from what I've heard you'd be crazy to swap out the GQ auto for a T700.

If the box is a Jatco, from memory the O'drive lockup only operates when engine is at or approaching operating temp. I had a friend with a skyline, and it took at least 5km before the thing would select 4th and lockup. This was normal apparently. I would be checking the temp signal input into the ECM to check it's accurate and working.

Just a thought.

JC

slosh wrote:

RoeDao wrote:
If it comes to poking a TH700 on it, i'll worry about it then. 1,200 bux for a transfer adaptor and the G/B.. BAH! it's only money right?

I am no expert, but from what I've heard you'd be crazy to swap out the GQ auto for a T700.

Why wouldn't you go with a T400? They are stronger.

Says HnM who knows nothing about the workings of auto's.

slosh wrote:

RoeDao wrote:
If it comes to poking a TH700 on it, i'll worry about it then. 1,200 bux for a transfer adaptor and the G/B.. BAH! it's only money right?

I am no expert, but from what I've heard you'd be crazy to swap out the GQ auto for a T700.

therein lies the problem.... 1,000 people will give you 1,000 different pieces of advice. I was told that the GQ Nissan auto will more than take the power of the 5.0 litre. Others say i will need to upgrade the shift module to the GU one. Others say go for the TH700 *shrug* beats me....... I like the auto off-road, so i want to avoid a 5 speed conversion for now. like i said, if it lasts a few months... i'll do some overtime and swap the trans over

justinC wrote:If the box is a Jatco, from memory the O'drive lockup only operates when engine is at or approaching operating temp. I had a friend with a skyline, and it took at least 5km before the thing would select 4th and lockup. This was normal apparently. I would be checking the temp signal input into the ECM to check it's accurate and working.

Just a thought.

JC

it used to do that befiore the swap.... would only drop into overdrive a few K's down the highway. And it would stay there.... sometimes it was a pain to get out of overdrive. Now, it does the same thing, few K's down the road, it drops in ok... only stays there for 10 seconds, comes back out, and stays out until i turn the ignition off to reset the gearbox ECM, whereby it does the same thing again. going into town in a few mintues to book it in for a major service.

Keep in mind, when i bought the Pootrol.... i did a service on the engine.... worked out from the markings on the air filter, and state of the oil and oil filter, it had been a few years since the vehicle was serviced properly. I haven't had the time or the money (since deciding on the swap) to organise it (trans service).... the engine swap may have been the last straw for it......

found out what could be possibly causing it seems the trans ECU needs a tacho signal for overdrive to work... i don't have the adaptor on it.... so it looks like a manual lock up is the go piece of piss to do.... gonna sort it after it's serviced next monday.... driving around and pulling it back gears as i corner or take off seems to be lightening the load on the trans and it is working a bit better. Part of the overheating issue could well be the fact that when cornering, it's not changing back gears properly, and it's under load accelerating from low speed in 3rd or 4th gear. I will need to adjust the TPS a bit more.

apparently, even the tacho adaptor isn't going to fix the overdrive issues... so i connected a switch and run it manually. Works a treat!! Also got the trans serviced today, and it's like driving a new car!! i'm stoked!! the mechanic made a new bracket and adjusted the TPS better... it holds gears now, changes when it's supposed to, and won't slip any more. Apparently thats what was giving me the heat problems. Without the TPS in the right position to ramp up the pressures internally, the bands don't function as they should. If i had of driven it to Rover Park this weekend the way it was, i would have been trailering it home. Bartso has the tacho adaptor and his doesn't work either...... i can even feel it accelerating better now. My fuel economy should improve a heap!!