my apologies in advance, I posted this in another thread regarding the cluster swap but I'm hoping someone will see this whos had the same issue and came across the culprit/ solution
Just completed an SR5 Cluster swap and oil pressure sending unit for my 84 DLX Xtra cab. Everything is working properly, but my Speedo is way off. The needle for the speedo doesn't start to move until the truck is going about 30 MPH. What did I do wrong? I've read threads about folks having to adjust the potentiometer to get the tach to work properly, but nothing for the speedo. Anybody experience this after the mod?

P.S. the cluster has only been on the truck for about 12 hours and about 100 miles. I've taken the dash apart and inspected the speedo cable male and female end in relation to the cluster. I drove around with the dash cover portion off (while fiddling with the back of the cluster and speedo connection, but it still displayed the same symptoms and the needle didn't engage until about 30+MPH. I posted this on FB and a member mentioned I may need to swap out the gearing for the speedo. Others have mentioned that the cluster will work a bit funky for a couple days and then just randomly corrects itself. Any help would be much appreciated.

 

Make sure the accelerator cable is fitting properly some years have different size openings on the back of the cluster. Remove the sr5 cluster and compare it to the opening behind your old cluster. If they do not match swap them over.

At the very least it's not a gearing issue. If it was it would still read as soon as you start driving but it would read higher or lower but it would still read something as soon as you drive. From the sounds of it it's free spinning for a bit until it bites or gets caught

 

thank u.