Hi

Car is a 4.4 V8 2003 (ZF 5spd box) with 124k miles.

My gearbox overheated- I know this because the limited gears policy was enforced and the car did not shift over 2nd. Once the car was left to cool for half an hour it went back to normal. The engine management light has come on- I had to drive with the limited gear selection strategy for at least 2-3 miles (dual carriageway).

I had the engine cooling system replaced 4 months old. The radiator, water pump, thermostat, hoses, coolant etc are all new- so I know the culprit is not the engine radiator.

I suspect blocked lines/ gearbox cooler and gearbox filter. I'm now trying to determine what the best course of action is. Would appreciate your inputs.

So I can either:

1) Get the gearbox flushed, ATF replaced

or

2) Bite the bullet and get a reconditioned box and TC

I'm not sure if (1) presents a long term solution. I have a feeling the box is knackered- its been run 123k miles on original fluid, so don't see how changing the fluid now will extend its life much longer. Do you agree?

How many miles do people usually get after changing the fluid so late? If its only around 10k before failure due to running on old fluid for so long- maybe I should go with (2) and just focus my efforts on finding a good gearbox rebuilder...

Value your input.

Not sure where you are in London but there is a great guy that repairs or rebuilds auto boxes on canvy island
Good prices to 1994 softail full stars n stripes custom harley davidson

I had a similar problem however I received the "transmission overheating" error message on the dash. My gearbox was replaced a couple of years ago and radiator etc replaced a year or 2 go so thought unlikely for those to go again.

My transmission oil wasn't actually overheating but the sensor had gone bad and wasn't resetting, tricking the system into thinking it was.

This came up on a diagnostics so beat to get that done before ou make any major decisions. I had the wiring loom replaced (contains the sensor) and gearbox fluid and filter etc changed. Cost £500 but problem fixed for another 100k miles.

Yes, certainly worth testing the resistance of the fluid temperature sensor with a multimeter before spending any money.

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See my previous post at bottom of page,I did option one originally and was a complete waste of money unfortunately.I'm currently over 121k and no problems with gearbox or TC since...

http://www.fullfatrr.com/forum/topic20037.html

Hi

I read your post- so I take it your saying the gearbox oil cooler could be the culprit and if doing a gearbox flush/ filter replacement, replace that as well... What seems important to note is that I think (if I calculated right) you did this at around 90k miles, mines at 124k at the moment. I think its reached the end of its life- as its probably clogged up by about now...

I'm fairly sure that this is not a thermostat issue because if the cars driven on a cold day on a short trip, the problem will not appear so it does appear to be temperature dependant.

Still contemplating what to do.

Can anybody recommend a gearbox rebuilder around Heathrow?

hy

My symptoms were the same as regards temperature.Sometimes on a cold day it wouldnt appear as maybe I guess the colder outside temp would help keep gearbox temp a bit lower and help prevent heat buildup.The gearbox cooler was the culprit and when we inspected the old one after changing it the inlet was heavily caked up restricting oil flow through the cooler.

Question is aside from the overheating have you been getting any other symptoms of a failing gearbox or torque converter.personally if not and this is only a recent issue I would only change the fluid,filter and cooler,flush the box and TC and leave it at that.

There is a nice howto on here by Saint.v8 on changing the transmission oil cooler for a V8, reporting the same symptoms as the OP.

http://www.fullfatrr.com/forum/post201196.html .
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Okay, you've convinced me.

I'll give a gearbox service + oil cooler a go and see how I get on...

How long do these transmissions usually last? Bearing in mind I have no evidence to suggest mines ever had the filter/ fluid changed. Anybody get more than 130k?

my cars previous owner (2002 v8 petrol) had autobox overheat, changed cooler rad, and then the box itself, still got hot, it was a 'collapsed feed pipe' (transmission cooler pipe from box to rad.)flexible part internally blocked. it had strangled itself. expensive fault finding. (for him)

Ouch, what a nightmare

At least you benefited in getting a recon box though! Should get my filter out sometime this week and find out if its ever been changed.

remember, when you change your gearbox oil, you are only 'changing' the bit in the gearbox, you cant drain what is in the torque converter. (a few more litres) so, if you are doing a 'best' job, you might want to change it soon after the first time. it will have mixed with the old and sort of given you a better longevity. you could perhaps remove each end of the trans pipes, and perhaps attach some rubber tube, and pour fluid through to test their flow.

be careful, and good luck.

Thanks... I'll do the initial flush plus cooler replacement, drive it for a week and see if it cures the overheating...

If so I'll do another flush. Otherwise I need to go back to the drawing board to figure out the cause of the overheating.

But taking the advice from your posts, I'll focus on the filter/ cooler before throwing out everything but the kitchen sink (recon gearbox)...

let us know how you get on after the work gets done,fingers crossed