Transmission (gearbox) Oil Replacement on 2005 Fiat 2.8 JTD
Having read many reviews on both here and the Fiat forum regarding the best way to replace transmission, gearbox oil, I managed to replace mine on a 2005 Hymer B524, Fiat 2.8 JTD over the weekend.
I managed to obtain the correct oil as per Fiat specification, Tutela, ZC 75 Synth., SAE 75W/85 (full synthetic) but only from a main Fiat dealer.
Cost for 3 Ltrs. including VAT was £28.00..
Could not find any other oil to the "exact" spec., so was happy to pay the Fiat main dealer in the end for the real stuff.
Getting the oil out is absolutely no problem, drain plug at bottom of casing, need a 8mm. square key or socket adaptor for the plug.
May have to jack up one front wheel slightly or drive up on ramps / planks to obtain sufficient clearance for a drain container.
It`s best to measure the oil quantity removed, mine was 2.5 Ltrs. approx., in theory should have been 2.7 Ltrs..
Getting the new oil in, not so easy !
Note, there is no sight glass or filler plug level as such, all the old oil is drained and the correct quantity of new oil is added.
There are a number of excellent posts regarding this on this forum and the Fiat forum, some with photos, very helpful.
The general consensus of opinion was to fill the gearbox via. the reversing switch mounting hole although Fiat I believe recommend filling by the "breather plug" mounted on the top of the gearbox casing.
Neither of these points are easy to get at especially on an "A" class m.home with smaller engine opening.
I found it best to fully remove the air filter complete body tying back the bottom air hose to reveal the top of the gearbox.
I could now just about see the reversing switch but there was no way I could get the electrical connector off to remove the switch, it was tucked away behind the engine mounting bracket.
Then I discovered the gearbox vent cap, more to the center of the engine and much more accessible.
The top cap came off this easily with finger pressure only required.
Their appeared to be a good fluid path to the gearbox, approx. 1/2" diameter.
I had on hand, a 13" length of 1/2" OD / 3/8" ID clear plastic tubing, bottom end fitted the vent plug hole perfectly, top end attached to a small plastic funnel.
Very slowly, 2.7 Ltrs. of oil was added to transmission, not difficult with the clearance produced by the air cleaner filter body housing but slow, allowing the air to relieve up the tube after every "slug".
Most people report that Fiat stipulates 2 Ltrs. of oil, 2.7 Lrts. is widely recommended to ensure lubrication of the fifth gear cogs as this was a common point of failure on the 2.8 JTD models.
My vehicle handbook actually states 2.7 Ltrs. for transmission.
The job is not as daunting as I thought, the most difficult part of the operation in my case being getting the top cover off the air cleaner housing, this should not be as difficult on a coach built van.
Hopefully this information will be of use to anyone contemplating this activity on a similar vehicle.