I'm approaching two years with my truck, and it wasn't until yesterday that I was able to solve a problem I've had since day one. I think I mentioned at some point in this community that I had problems shifting into reverse in my truck, which has an automatic transmission, because when I did so, there was sometimes a knocking sound that could even be quite loud. Since this knocking was not frequent, I decided not to pay much attention to it. On one occasion, I took the truck to a friend who is a transmission technician, and he told me that I wouldn't have any problems in the future because of that knocking sound, that it was probably just a matter of the truck being a little revved up and that this could happen as a normal occurrence.
However, in recent weeks, it was no longer a knocking sound, but rather a sound like two gears rubbing against each other, which was quite loud and prolonged. Although it didn't happen every time I put the truck in reverse, it was becoming alarming. And, as we all know, anything related to an automatic transmission can lead to high costs in the future.
Fortunately, I have a mechanic who is an expert in this type of truck, who told me that it was impossible for the problem to be directly related to the transmission, since there is nothing in the transmission that could generate a noise like this, or even the same knocking sound. So everything indicated that the transfer case needed to be thoroughly checked. The transfer case, for those who don't know, is an appendage or sort of appendage that the transmission has, which allows the truck to be 4x4 and to apply 4x4 high and 4x4 low, as well as other functions that I honestly don't know about. It turns out that when you apply any speed to the gearbox, the transfer case also performs a function that, in this case, was affecting when I applied reverse.
When we opened the transfer case, the first thing we noticed was that it had very little oil. According to the user manual, the transfer case should contain 1.4 liters of 15W-40 engine oil, and it had, honestly, about 300 milliliters, so it was missing a large amount. However, we did not conclude that this could be the only problem. So, as we investigated further, we realized that there were two forks, which you can see in the photos, that were quite worn and no longer had rubber covering the outside.
These two U-shaped rubber or plastic pieces, which cover the fork, were out of position and even loose in the transfer case. This was compounded by the fact that the forks were quite worn. The noise was caused when these forks did not fit properly into the gear, and the noise I mentioned, which was quite prolonged, was generated when the gear and the fork collided and repelled each other because they did not fit together correctly.
Once the problem was identified, the mechanic, taking advantage of the fact that the fork is made of iron and not aluminum, filled in the most worn parts with weld and then shaped them with a grinder to restore them to their original size and shape. Additionally, we rebuilt the plastic covering the U-shaped fork and secured it with wire so that it would not come out of position again in the future. After doing this and preliminarily assembling the transfer, we noticed that there was no longer any play between the parts. Everything felt quite tight, unlike when we first uncovered it, when it was clear that some parts seemed loose.
In addition to rebuilding the forks, we noticed that the oil filter was quite dirty. We proceeded to clean everything and bought 1 liter of oil to top it off. Everything indicated that after the maintenance and cleaning of the transfer, everything should be in working order.
So, after assembling the transfer and installing it along with the box, the cardan shaft, and other elements, we proceeded to test it, and the result was impressive. Never since I bought the truck had I felt the reverse gear engage or reverse so smoothly. There was always some noise, sometimes faint, sometimes very loud, but there was always noise. Now, however, when I shift into reverse, there is complete silence, so it became clear that the problem was in the transfer case. I hope it stays this way, as it was a problem that caused quite a few headaches.
I was quite satisfied with the work. Now it remains to follow up and hope that these fork rubbers stay in position so that they engage or integrate with the gears correctly. I was quite satisfied, and now I know that my truck's transfer case is in very good condition, with new oil and rebuilt parts that, from my point of view, will not bother me or cause problems for a long time. It was a pleasure to share this experience. See you next time.
-Used tools/Herramientas usadas:
- Traductor: DeepL Translate
Bravo to the technician 🫡.
These are definitely the consequences that arise when our cars are that old. The sound was already a warning, and the lack of oil was surely one of the main causes that led to the wear on the shift forks. It's great that you were able to rebuild them and seal everything up properly