Tahoe Q4 movement during transport

Had this issue since we bought it last year.
2007 Tahoe Q4 w/ 4.3L engine on a Tahoe trailer. Minn Kota Trolling motor installed with 2 batteries on rear to the left of the engine battery.
Issue: No matter how we load the boat, the bow moves to the left to where the bow almost comes off the roller. Bow moves about 2".

Tried: -Tightening bow strap tight to almost banjo tight
- Checking to see if bunks are square (they seem ok)
- Loading slightly off center toward low side (some success) about 1"
- Checked leaf suspension to ensure they are even side to side (both seem fine)
- Adjusted stern safety straps to ensure they are tighter on high side. (low is 36" and high is 37" from ground to trim line on rear measuring point)

I am at a loss for what could be causing this. Dealer said to replace the leaf suspension but it seems fine with no sag or access bounce. Someone said Tahoe's, since they have long trailers, is to put a small ratchet strap on bow ring straight down in addition to winch strap on trailer to prevent lifting on bumps.

It is causing damage to gel coat and I will be getting a stainless bow guard installed but I need this boat movement issue resolved. Has anyone run into this issue? What's the best way of checking bunks for squareness? I measured from end corner to trailer fram edge.

When you say you checked the bunks... are they centered to the trailer and bow stop? I've seen on more than one occasion the stop not be square to the trailer and or the winch stand be twisted... (power loading usually and being too deep and hitting it hard). The perspective on your photo makes it hard to tell but looks off center... if you float it off a bit then hand winch up the trailer when level, does it pull up to the bow stop level?

I'd be focusing on the lower set of bunks in the forward section. See if they are exactly the same in terms of their height off the cross bar and centering.

You could take a picture of that area once the boat is first loaded, and then again after traveling, when the bow is off center.

If it were my trailer, I would make the bunk mounts non stationary. The bunks can be to rigid and force the boat off center. All my trailers over my 60 years of boat ownership have had supports the can move to allow the bunks or rollers to adjust themselves to match the hull. Never had an issue doing it this way. With everything rigid, all support must be in perfect alignment or your off center or tilted crooked.

Pmt133 said:

When you say you checked the bunks... are they centered to the trailer and bow stop? I've seen on more than one occasion the stop not be square to the trailer and or the winch stand be twisted... (power loading usually and being too deep and hitting it hard). The perspective on your photo makes it hard to tell but looks off center... if you float it off a bit then hand winch up the trailer when level, does it pull up to the bow stop level?

Click to expand...

I do not drive the boat onto trailer because it is not steady enough in idle due to stern drive. I float the boat onto trailer then winch the last 3 feet. It centers on stop each time. It just moves after travelling about 30 miles.

tpenfield said:

I'd be focusing on the lower set of bunks in the forward section. See if they are exactly the same in terms of their height off the cross bar and centering.

You could take a picture of that area once the boat is first loaded, and then again after traveling, when the bow is off center.

Click to expand...

I will be refloating the boat today and will try that. Thanks.

Despite the title I was not completely clear on the issue: at loading (i.e. will not center) or post traveling down the road. Your post #5 answered that question so now I understand that your boat is bouncing around on its cradle while traveling down the road.
Two things I noticed in your pics:

1. One of your lower bunks seems to be only tied to its support with some rope. See screen shot close-up of one of your pictures. While I do not think this is the root cause, it is not good and this and any other issues impacting the integrity of the trailer should be addressed first.
2. It may be the angle of the pic but it looks like your axle is too close to the frame, see other screen shot of pic. This could lead to a strong jolt to the frame / boat when going over rough roads. I do not see where the frame paint is damaged, but a closer inspection is warranted.

I am not an expert, but I am of the understanding the boat and the trailer should be ‘as one’ once loaded. To accomplish that I do some extra strapping. Let me explain:
The winch on the bow eye, regardless of how tight, will not keep the bow from moving side to side > you can always get a little side to side wiggle room since the wench strap really holding it from sliding off the trailer. Its not holding the boat with down force in its cradle. The strap straight down fm the eye you installed was in the right direction but clearly not enough. What I do is use the port and stbd bow cleats to hold the bow down as well as prevent forward motion. Here is how:

• Using a twisted eye lifting strap, I pass it under the cleat and fold it in half. This brings the strap eyes together with the doubled-up strap passing across the top and down the side of the boat. A boat buckle is hooked into the straps eyes and the other end is hooked onto an additional trailer bracket I installed. The overall angle of the straps are slightly to the rear so these not only hold the bow down but also preclude forward movement in case of sudden stop. I also do the same (except straight down) from the aft cleats. All this in addition to the transom staps. So, 6 in total + winch + safety chain. I thought I had some pics of this set up but could not find them. And unfortunately, I cannot take any as our boating season did not happen this year and boat is already wrapped. So below is a mock up I made up to give you a better idea.

I am sure some would consider this overkill, but I can tell you my boat and its trailer are one solid unit.
My suggestions:

• Thoroughly inspect the trailer and bunks and correct any issues.
• Strap the heck out of it.
  • Link to example twisted eye lifting straps (the twisted eye on each end allows the two eyes to be nested for the buckle’s hook)
  • Link to example extra trailer hold down bracket.

ESGWheel said:

Despite the title I was not completely clear on the issue: at loading (i.e. will not center) or post traveling down the road. Your post #5 answered that question so now I understand that your boat is bouncing around on its cradle while traveling down the road.
Two things I noticed in your pics:

1. One of your lower bunks seems to be only tied to its support with some rope. See screen shot close-up of one of your pictures. While I do not think this is the root cause, it is not good and this and any other issues impacting the integrity of the trailer should be addressed first.
2. It may be the angle of the pic but it looks like your axle is too close to the frame, see other screen shot of pic. This could lead to a strong jolt to the frame / boat when going over rough roads. I do not see where the frame paint is damaged, but a closer inspection is warranted.

I am not an expert, but I am of the understanding the boat and the trailer should be ‘as one’ once loaded. To accomplish that I do some extra strapping. Let me explain:
The winch on the bow eye, regardless of how tight, will not keep the bow from moving side to side > you can always get a little side to side wiggle room since the wench strap really holding it from sliding off the trailer. Its not holding the boat with down force in its cradle. The strap straight down fm the eye you installed was in the right direction but clearly not enough. What I do is use the port and stbd bow cleats to hold the bow down as well as prevent forward motion. Here is how:

• Using a twisted eye lifting strap, I pass it under the cleat and fold it in half. This brings the strap eyes together with the doubled-up strap passing across the top and down the side of the boat. A boat buckle is hooked into the straps eyes and the other end is hooked onto an additional trailer bracket I installed. The overall angle of the straps are slightly to the rear so these not only hold the bow down but also preclude forward movement in case of sudden stop. I also do the same (except straight down) from the aft cleats. All this in addition to the transom staps. So, 6 in total + winch + safety chain. I thought I had some pics of this set up but could not find them. And unfortunately, I cannot take any as our boating season did not happen this year and boat is already wrapped. So below is a mock up I made up to give you a better idea.

I am sure some would consider this overkill, but I can tell you my boat and its trailer are one solid unit.
My suggestions:

• Thoroughly inspect the trailer and bunks and correct any issues.
• Strap the heck out of it.
  • Link to example twisted eye lifting straps (the twisted eye on each end allows the two eyes to be nested for the buckle’s hook)
  • Link to example extra trailer hold down bracket.

View attachment 411052

View attachment 411053

View attachment 411054

Click to expand...

Thanks for the input. The bunk photo was one I used while centering the bunk thus why it is held by paracord temporarily. It has been secured with a bolt. I guess I should have created a new photo. I will look into those twisted eye straps. The straight down strap on the bow was one sent to me and I don't have that style, though I do use a small 1500LB ratchet strap there. Currently it is straight down, so I might move it back a bit. I even contemplated using the side trailer beam opposite of the way the boat is moving in order to create "Tension" in the direction I want it to go. I just remeasured all the bunks and they are square to the boat and side to side. I'm thinking since Tahoe's like this one have such long trailers, there could be trailer flex causing some of this. I agree some extra tie downs should basically weld the boat to the trailer and make it "one" as you put it.

ESGWheel said:

Despite the title I was not completely clear on the issue: at loading (i.e. will not center) or post traveling down the road. Your post #5 answered that question so now I understand that your boat is bouncing around on its cradle while traveling down the road.
Two things I noticed in your pics:

1. One of your lower bunks seems to be only tied to its support with some rope. See screen shot close-up of one of your pictures. While I do not think this is the root cause, it is not good and this and any other issues impacting the integrity of the trailer should be addressed first.
2. It may be the angle of the pic but it looks like your axle is too close to the frame, see other screen shot of pic. This could lead to a strong jolt to the frame / boat when going over rough roads. I do not see where the frame paint is damaged, but a closer inspection is warranted.

I am not an expert, but I am of the understanding the boat and the trailer should be ‘as one’ once loaded. To accomplish that I do some extra strapping. Let me explain:
The winch on the bow eye, regardless of how tight, will not keep the bow from moving side to side > you can always get a little side to side wiggle room since the wench strap really holding it from sliding off the trailer. Its not holding the boat with down force in its cradle. The strap straight down fm the eye you installed was in the right direction but clearly not enough. What I do is use the port and stbd bow cleats to hold the bow down as well as prevent forward motion. Here is how:

• Using a twisted eye lifting strap, I pass it under the cleat and fold it in half. This brings the strap eyes together with the doubled-up strap passing across the top and down the side of the boat. A boat buckle is hooked into the straps eyes and the other end is hooked onto an additional trailer bracket I installed. The overall angle of the straps are slightly to the rear so these not only hold the bow down but also preclude forward movement in case of sudden stop. I also do the same (except straight down) from the aft cleats. All this in addition to the transom staps. So, 6 in total + winch + safety chain. I thought I had some pics of this set up but could not find them. And unfortunately, I cannot take any as our boating season did not happen this year and boat is already wrapped. So below is a mock up I made up to give you a better idea.

I am sure some would consider this overkill, but I can tell you my boat and its trailer are one solid unit.
My suggestions:

• Thoroughly inspect the trailer and bunks and correct any issues.
• Strap the heck out of it.
  • Link to example twisted eye lifting straps (the twisted eye on each end allows the two eyes to be nested for the buckle’s hook)
  • Link to example extra trailer hold down bracket.

View attachment 411052

View attachment 411053

View attachment 411054

Click to expand...

I measured the top of the axle to the trailer frame and it is 2 1/2" on each side and no visible damage or scoring on paint so I don't believe it is hitting.

airshot said:

If it were my trailer, I would make the bunk mounts non stationary. The bunks can be to rigid and force the boat off center. All my trailers over my 60 years of boat ownership have had supports the can move to allow the bunks or rollers to adjust themselves to match the hull. Never had an issue doing it this way. With everything rigid, all support must be in perfect alignment or your off center or tilted crooked.

Click to expand...

Never heard of non stationary bunks or rollers.

redneck joe said:

Never heard of non stationary bunks or rollers.

Click to expand...

Extremely popular on many trailers. There is a pivot point where the roller or bunk can move or flex as the boat loads so the bunk or roller can make full contact with the hull. I used to set up trailers at a marine dealer some years back. 75-80% of the trailers had adjustable rollers and bunks. The wobble rollers replaced the self adjusting roller mounts, but many mfgrs still make the pivoting mounts especially for bunks. The mount allows the bunk to move a small amount as the boat loads, this keeps max contact to the flat surface of the bunk board. Makes loading much easier than n my opinion.