I’ll not say there’s anything particularly wrong with Dexron, more that it’s designed for something else. I think the specs and licences for Dexron III and down have expired so you may be trusting the manufacturer on what you get. Earlier versions of Dexron are hygroscopic, which isn’t such a problem in a transmission, but may be in a steering box. The friction modifiers are designed to allow a slip and then lock behaviour in transmission clutches.
The fact is that Dexron, brake fluid, engine oil, and a lot of other fluids may be fine for a long time in a steering box and pump, but they weren’t designed for it. Personally, I’d do as Tigger says and use Castrol TQF.
Whenever a lubricants question arises, we have the same sort of discussion. The fact is that a definitive answer can be provided only by someone who’s worked in the area for an oil major. That also excludes me. I have worked in an oil products development company, but not in lubricants so my knowledge is secondhand and to some degree out of date, though I have tried to follow the subject.
If you want the best advice, log into or search the forum of the S-type register. You’ll find Glyn Ruck who was a global lubricants expert of a major oil company. I’m sure he’ll agree on Dexron. The problem, or good fortune, is that modern lubricants are very good. The wrong ones will nine times out of ten work very well, but that’ll not make them the ideal fluid. Does it matter? Perhaps not that much in many cases for a car that goes out only a few times a year. Maybe it’ll be trouble for the next owner or the one after. On the other hand, I really want the best for my Jaguar.
That’s a good answer. I was just wondering why he put it in caps.
TQF is to spec and so it is perfect.
Sometimes oils don’t work universally, GL5 gearbox oils can eat brass, transmissions and gearboxes rely on different friction characteristics, but Dexron 3 is pretty mild (too slippery for some transmission clutches…) and I’d assume that the materials in transmissions are the same as in steering boxes. But yes of course not using the right oil when it’s available doesn’t make sense.
After market additives are to be treated with a little caution. Oil majors spend a huge amount developing their products. The site where I worked had a staff of 800 to a thousand and the company had local products development and testing around the world, especially for the US and Germany. If an additive was generally so good and long-term safe, they would already have put it in the oil. That doesn’t mean they are all useless, but be careful, don’t rely on them or expect them to be a permanent solution, and don’t leave them in the system too long.
Mercedes isn’t my favourite car manufacturer, but they are very thorough in lubricants testing and setting specs for their cars. Fuchs Lubricants work very closely with them listing products exactly to M-B spec. If you go to the Fuchs Lubricants UK website and search Titan steering, there’s a list of fluids matching M-B specs. Basically, there’s Titan PSF which isn’t an ATF. The only ATF matching a Mercedes spec is a type A.
You mentioned GL5. In fact, there’s a Ford spec that’s good for our old gearboxes. If you go through the list of Castrol MTFs, you can find the ones that satisfy it.
So, since I already basted it out once, I should consider two more bastings as a possibility to completely eradicate the noise if necessary. Before commencing two more bastings, I’m considering driving the car one or two more times to see if the ‘exercise’ might cure the noise. I do know the noise, while still present, subsided sooner when driving, after the first basting. I will still go out and purchase several more quarts of ATF to keep ‘in reserve’ if future bastings might be required. The question is now should I search for type F, which I just used for the first basting, or, as Tigger suggested should I look for Castrol TQF, and will type F and Casrol TQF be compatible?
I think TQF is a type G, at least in the UK, which is very close to type F but higher viscosity. I don’t think there should be any problem in mixing them. Personally, I’d drive the car a bit if only to mix the oils up. If the noise goes away, leave it. If not, then try to remove some more oil. Have you changed the filter? If not, do that at the same time.
Thanks to this thread, I’m re-learning a load of stuff that I’d long forgotten. It will be helpful when (or if) I get to the steering gear on my Mk2.
Peter
I changed the filter less than 2000 miles ago two years ago, so I think it should be ok. I cannot find TQF on the websites of various US automotive supplier stores, but plain type F is available at various locations. So, since I just added in a quart of type F several days ago after basting out the old Trans X which was in there, I’ll purchase a few quarts of type F to keep in reserve, but drive the car a few more times to see if the noise may subside further. If not, I’ll do another basting or two with type F.Hopefully this will work. Thanks
I mentioned earlier I replaced the filter two years ago and drove the car 2000 miles since then. My question now is, did the trans x fluid addition two years ago while helping the seals to no longer leak, possibly clog the filter at the same time? Perhaps if I ordered a new filter now might it help solve the noise problem?
I don’t know if the anti-leak could have blocked the filter. I don’t see why it would, but I’ve no idea how it works. I think I’d drive the car a bit more and see how it goes. If the noise persists, do some more oil changing and swap the filter.
Incidentally, in case it’s not obvious, the F and G at the end of the Ford specification numbers in David’s pdf is where the type F and type G come from.
I bought two quarts of type F today. I’ll continue to drive the car a few more times. If the noise persists I’ll do another fluid change. For the moment I won’t change the filter. Thanks
This has been on my mind - At the risk of stating the obvious, is the squeal the drive belt slipping? Check tension and also ensure no grease / oil on pulleys. To ensure clean, one method is when engine is running, spray a little brake cleaner on the pulley / friction side of the belt.
I appreciate the input, but I can tell you for certain the noise is not a squeal but rather a groan. With the engine not running, if I turn the steering wheel side to side the noise appears. The good news, however, is since I vacuumed out old fluid from the power steering reservoir and replaced it with type F fluid, the noise has been diminished somewhat but not eliminated completely yet. Though I haven’t driven the car for the last 7 days, I’ve 'visited it in the garage every day since and with the engine off, repeatedly turned the steering wheel side to side several inches in both directions. When I visited it yesterday, it barely made any sound at all. In two days from now I’ll have the opportunity to actually start it up and go for a drive. I’ll post results afterwards,
One thing you might try (if you haven’t already) is to jack up the front of the car to take the load off the tires and cycle the steering from lock to lock a number of times. There might be some air trapped in the system. Does the noise diminish or stop if the load is taken off the tires?
UPDATE
After several exercises of withdrawing power steering fluid from the reservoir with a ‘baster’ and replenishing with automatic transmission fluid type F, over the last few weeks, I’m pleased to report the following: When I entered the garage this morning, turned the key and started up the car I experienced a joyous 14 mile drive without any noises whatsoever emanating from the steering mechanism. It’s cured! Thanks to all for your sage advice.
Cheers
Mel R.