PPP & FR Multilink taking output drops

I am dealing with couple of issues where we have two different Multilink bundles on two different routers and for both of them the technology is defferent one is of PPP and the another one is Frame-Relay.

On both the bundels i am getting high output drops. QOS is implemented on both the bundells and we are using class-based queuing on both of them. We have four different classes created on policy i.e Voice, Voice Control, BGP Control, Production & class default. And they are arranged above as per their precedence value.

When i checked QOS i found its just the Class Production which is taking errors and the precedence for class production is 3. I did some research but didnt really find the solution for this. I tried increasing the allocated bandwidth to CLass Production but that also didnt help.

Now i put the 180 vlaue for Queue Limit under the Class Production and output drops have decreased big time or i would say they decreased to 0 (Zero) for PPP Multilink but still they are increasing on Frame-Relay one probably i need to increase the Queue Limit for FR multilink.

I just want to confirm is there any other solution to this problem than putting the Queue Limit value and also since this solution is working for me almost on both do we have any negative effact because of this?

I would wait for the you opinion on this......request you to reply asap since i am dealing with this issue in real time.

Cheers )

Nitin_Virmani