The serial numbers are 'hand' stamped on the bottom of the txb, as fitted, but the other side (of the bottom) to the drain plug. ie. Look up from ground level, spot the drain plug and look to the other side.
If you have a turbo and the serial number does NOT begin with a 'Y' then it is a non-turbo box and should not have been fitted. The viscous coupling will deliver less drive to the rear wheels. This means it is less able to deal with such things as wheel spin and because it cannot stop the spinning, by delivering the correct drive to the rear wheels there is a chance that the txb can overheat, either way you loose traction. Careful driving will help the situation but is a contradiction to the term 'turbo'.
Put another way, however you drive the car, the maximum drive that can be delivered to the rear wheels will have been reduced to that of an 8v or 16v, so traction will not be so good.
The absolute worst case is that you have an 8v txb with an 8v front end prop coupling, on a turbo car. The coupling is larger, and stronger, on the 16v and turbo variants.
Given the apparrent history of the txb, have a good look at the two joints on the txb which are held together with nine hex bolts. The txb is in three parts, the large front end, the middle one inch, which houses the ram seal and the large rear end which houses the viscous coupling. The mating surfaces should be sealed with an instant gasket cement eg 'Carplan' - as there are NO gaskets. May just not be properly tightened or sealed properly.
On your posting at 0850 on the 11th, the photograph, from my Workshop Manual' shows a 2-wire temperature sensor. Here is a better view:
It is the one with the green top. All the other items around it are txb mounting bolts. The hole the sensor is in was the filling hole on the earliest txb's and it simply had a 'drain plug' type plug in it. It would have a tapered thread. The later model had a single wire temperature sensor in exactly the same place but it was a smaller hole. The sensor is very similar to the one found in the thermostat housing for the water temperature gauge.
The purpose of the temperature sensor is to detect when the txb oil temperature rises to about 160 degs.C. It then shuts the box down to avoid any damage.
This photograph:
is the best I have to give you a clue where to look. This shows the area under the bulhead where at the top of the picture is the plastic flap which runs accross the top back of the bulkhead. Having spotted the accumulator assembly in the picture, lift the flap on the other side above the water header tank and you should find a connector with either a temperature sensor fitted to the plug ends or doctored in some way.
1. If your car is the single wire version I would bet money the temperature sensor is still connected and unfortunately measuring the ambient temperature under the bonnet.
2. If the car is a 2-wire version either:
a. The temperature sensor is not connected and the two wires of the socket are connected together or
b. The temperature sensor is still connected.
Have a look and let us know what you find.
You can try ringing Ultravaux but I doubt you will get any joy. I have been trying all morning because I need to talk to them about a copyright infringement on the Dorfbrunnen photo they are using.
Incidently if you go to the search engine
Google.com and do a search for 'ultravaux' you will see them listed as 'Car Breakers'
Hope this all helps
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