I have a very similar problem. Here are the specs. 85 4Runner, 22RE, W56-A, 2.28 front case, MC # 1095, mc 4.7 rear case.
I am hearing the same whirling, howling noise. It happens at about 35 to 45 mph and gets worse at higher speeds. It only happens when load is taken off of the drivetrain such as a downhill portion of the road when you take your foot off the accelerator. If you push in the clutch when this is happening, the noise continues and you can keep it howling loudly almost to a dead stop if you hold the clutch in. Putting it in neutral does not make the noise go away.
I wish I would have taken out the rear driveshaft and tested it again, but I don't think that the driveshaft is the problem.
Being not as gear savy as some of you guys (yet), I have been taking the "lets try this and see if it works approach"
I replaced the clutch pilot bearing, throwout bearing, and went ahead and put a new MC clutch. To me this seemed like the place that I would have been getting the most play in the drivetrain. I put it back together and found that this was not the answer.
I now have the tranny/t-cases on the floor again and was planning on bolting my spare tranny up to the dual cases and putting it back in to see if it was a bearing or something in the tranny (A little background on the vehicle: I purchased it, slightly use, not long ago. when I changed all the fluids, I got a lot of metal shavings out of the tranny.)
While I have the tranny/t-cases on the floor I am going to replace a cracked cover #1 on the rear case (frontmost section if you don't have it memorized) and also put twin sticks.
So, here is the question. What do you guys think that I should do while I have it apart, given my above explaination? After reading 4RnrRick's conclusions, I might just keep my existing tranny, lube everything?, and reassemble. I don't really have the knowledge or tools to get to much into the internals of the crawl box or t-case, but I would appreciate it if someone could give me some specifics on what exactly should be checked and/or lubed while I have it apart. Is it as simple as putting white antiseize on the splines of the output shafts?
Thanks in advance,
Coyote
