I have a 91 Toyota V6 3.slow SAS with a V6 drive train and V6 4:10 in the rear and a 4cyl 4:10 up front with a long spline drive line.
When in 4wd, truck makes a thumping and popping noise. Is this due to 4cyl gears up front and V6 gears in the rear not matching up? I am confused as to why this is happening. I don't think it is the drive line because it's a long spline and a high angle and U joints are in really good shape. I'm still new at this and feeling lost...and need help. Any reccomendations for fixing this problem or trouble shooting ideas would be appreciated.

Went to off road shop today - they said it could be the constant velocity joint was the wrong set up. So I am purchasing a triple drilled TC flange to see if that helps for now???

Thank you

 

No.
The wrong setup? What the hell is that supposed to mean?
How is that going to help???

 

What they meant when they said wrong setup on the CVJ is not enough angle for my lift. They said it might be binding up. They gave this prognosis without fully inspecting the CVJ. I removed the driveline this afternoon and inspected CVJ. The people that I had build my driveline had already clearenced my CV properly - not the problem. Back to my original question - front diff with v6 rear diff... will they work together?

 

4cyl isn't as strong I believe. But it will work just fine as long as the gear ratio's match.

 

I pulled the diff, counted the teeth, 40 on the big one and 10 on the little one and pink pinion paint which leads me to believe it's 4:10

 

Ratio is all that matters. Only difference in 4-cly and 6-cyl gears is the dimensions of the ring and pinion gears, mainly the thickness differs.

One quick test you can try is to remove the rear shaft and then see if the front drive works all by itself (lock hubs and use 4H). If that is OK and assume RWD works fine, then just confirm the ratios are the same. And when you do the 4WD test, what sort of surface are you driving on? If it is a high traction surface and you are turning, you might just be seeing normal 4WD drive train binding.

 

Are your u-joints in phase?