Rebuilt M5OD-R1, clunks a couple times in 1st gear

[SamC777]

Hey guys, I just had my manual rebuilt in my 94 XLT. Thing drives fine with no issue, and I haven't driven it very long since reinstallation. As I listened closely today, whenever I shifted in first and gave her gas, I heard a "clunk clunk" as I moved forward and felt it in the shifter too. No sound after.

I got underneath to check the driveline, there was no play in the u joints or anything. This sound is not heard when I'm in reverse either. Any idea what this could be?

 

[RonD]

Reads like the slip joint needs to be lubed

Its on the drive shaft and has a rubber boot over it
You need to mark and unbolt the drive shaft from the rear axle
Slide rubber boot out of the way and lube the splines
If you want to pull out the drive shaft its not a bad time to replace u-joints just because, lol